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Alex Deleon’s MCAT Flashcards > Alex - CP - Flashcards (1) > Flashcards

Alex - CP - Flashcards (1)

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1
Q

How to apply stoichiometry to reactions, and finding % yield/empirical formula from reactant amounts

A

How to apply stoichiometry to reactions, and finding % yield/empirical formula from reactant amounts

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2
Q

How to find how much an object drops when thrown at an angle

A

How to find how much an object drops when thrown at an angle

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3
Q

J/C = electric potential; Electrostatic force = (kqQ)/r^2

A

J/C = electric potential; Electrostatic force = (kqQ)/r^2

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4
Q

Got the right answer but misinterpreted 2 kN as 2N and crossed it out, went with a different answer

A

Got the right answer but misinterpreted 2 kN as 2N and crossed it out, went with a different answer

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5
Q

What sign would Delta H have in an endothermic reaction? Would the reaction mixture be hot or cold?

A

Positive Delta H = endothermic (reaction gets colder)

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6
Q

On a titration curve, where can you find the pKa?

A

pKa occurs at the half equivalence point of the titration curve. Here, [A-]=[HA]. pH = pKa. Midpoint of the initital horizontal part of the curve.

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7
Q

What does the “SDS” do in an SDS PAGE? What are the charges of the anode and cathode? Where do proteins migrate?

A

SDS-PAGE uses a SDS detergent to make all proteins negative. Electrophoresis is an electrolytic cell. Anode = positive (higher potential) and the cathode = negative (lower potential). Proteins migrate to positive anode

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8
Q

Find Molarity of salt in ocean water, given density and there is __% of salt in typical ocean water

A

From density, assume 1 Liter is present and multiply by percent to get grams

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9
Q

What happens to BP after adding salt?

A

Adding salt reduces vapor pressure. Solute concentration increases, so rate at which water molecules break through surface is decreased. Boiling = temperature at which vapor pressure of a solution is equal to atmospheric pressure. Decreased vapor pressure makes this more difficult to achieve.

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10
Q

Which best explains why ice is less dense than water?

A

Bent structure of water and ratio of Hydrogens to Oxygens maximizes the hydrogen bonding that occurs in the solid phase producing a hexagonal structure with many open spaces

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11
Q

What is the formula of calcium sulfate?

A

Sulfate, SO4, is -2 charge and Calcium sulfate is CaSO4

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12
Q

Which are the products of the decay described in the passage to __ compound?

A

Beta (-) decay releases an electron and gamma rays are ionizing radiation

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13
Q

Why did they choose this type of people to study?

A

Passage analysis

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14
Q

Can we conclude this about the study?

A

Passage analysis

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15
Q

Gave torque and Force in the passage, find distance away from point the force is applied (r)

A

Torque = r * F * sin(theta)

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16
Q

Magnitude of force of an ankle that is turning is hypotenuse.

A

Magnitude of force of an ankle that is turning is hypotenuse.

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17
Q

What effect does a competitive inhibitor have on an enzyme’s Vmax and Km?

A

Competitive inhibitors increase Km and Vmax unchanged

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18
Q

Scientific notation conversions

A

Scientific notation conversions

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19
Q

A book rests horizontally on a table. The book experiences a gravitational force of mg due to the earth’s gravity. According to Newton’s third law:

A

Newton’s 3rd law does NOT apply to normal forces. Fa on b = -Fb on a.

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20
Q

Is a Lewis base a better nucleophile or electrophile?

A

A Lewis Base is a strong nucleophile, but N2 is an inert gas.

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21
Q

What is the electron configuration of acetone? What is its bond angle?

A

Acetone is sp2 and is trigonal planar with bond angle of 120 degrees.

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22
Q

Which band disappearance would you expect to see in a reaction where you go from ketone to alcohol?

A

Carbonyl stretching: 1700-1750, OH stretching: 3200-3500,

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23
Q

Which pair of amino acids would most likely form disulfide bridges?

A

Cysteine (C) residues form disulfide bridges

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24
Q

Which of these could be the reduction potentials of the final step in the ETC? (Given the reduction potentials of each step)

A

Passage analysis. (Understood this question, but it was hard and you had to think beyond what I did)

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25
Q

If Keq is positive, what is the sign for Delta G?

A

When asked to predict Keq or Delta G, remember Delta G = -RTln(Keq).

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26
Q

In what situation can total internal reflection occur?

A

Light entering a more dense medium bends towards the normal, meaning the angle of refraction is less than the angle of incidence. Internal inflection only happens when light begins in a high index material and goes to a lower index

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27
Q

Which of the following describe the orbital hybridization of NH3 and XeF4?

A

NH3 has 3 bonds and one lone pair, so it is sp3. XeF4 has 2 lone pairs and 4 bonds, so it is sp3d2

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28
Q

Which of the following solvents would most disrupt a protein made up of many Leucine groups?

A

Leucine is hydrophobic, so placing a protein made of Leucine in a hydrophobic solvent would most disrupt the structure

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29
Q

The association constant, Ka, is ___ for given equation. What is the Keq?

A

Ka, association constant, is an equilibrium constant and is equivalent (in this case) to Keq.

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30
Q

Which cation would form most quickly upon deprotonation?

A

Passage analysis. It gave a list of Delta H for the formation of each compound and I had to choose the formation with the lowest Delta H.

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31
Q

Passage analysis.

A

Passage analysis.

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32
Q

Is flourine a stabilizing or destabilizing functional group?

A

Passage analysis and Flourine is destabilizing because it is highly electronegative.

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33
Q

Under what conditions is the reaction spontaneous?

A

Passage analysis. When elements in their elemental state react to form a more organized compound, entropy decreases [(-) Delta S]. If Delta H is positive, then it is spontaneous at low Temperature.

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34
Q

If an object is halfway down a ramp and there is friction, how much force needs to be applied downward to keep it from moving?

A

The force required to halt the car is when friction = mg sin (theta)

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35
Q

The phenomenom of a “dry heat” feeling cooler is a result of: ?

A

There is increased evaporation of water (sweat) when you are in a dry climate because there is less water in the air and your body can more easily sweat.

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36
Q

Which of the following functions use microtubules?

A

Microtubules are used in the transport of vesicles and positioning of cell organelles. They are used by phagosome transport, mitosis and meiosis (spindle apparatus).

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37
Q

When can you use the stoichiometric coefficients in the rate law?

A

You can use stoichiometric coefficients for the rate law exponents in ELEMENTARY (single step) reactions

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38
Q

What factors affect Ksp?

A

Ksp only responds to changes in temperature. Decreasing temperature decreases Ksp

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39
Q

Can one compound have a Ka and Kb?

A

Ka and Kb are between the Ka of an acid and the Kb of the conjugate base. They both do not pertain to the same compound

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40
Q

What is the Pauli exclusion principle? What is the Aufbau principle? What is Hund’s rule?

A

Pauli exclusion principle-no two electrons can have the same exact set of quantum numbers. Aufbau principle-electrons fill orbitals in order of increasing energy. Hund’s rule-each orbital must contain one electron before any are paired.

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41
Q

What is the equation for effective nuclear charge?

A

Effective nuclear charge = Total #electrons of all shells preceding the principal number in question - #protons. Dont forget to change #protons if it is in an ion

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42
Q

Is CO2 polar?

A

Carbon monoxide is polar, but carbon dioxide is nonpolar. This is becase CO2 is symmetrical and the dipoles on either side cancel each other out

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43
Q

What is the geometry of carbonate?

A

Carbonate ion is trigonal planar. There are three substituents and no lone pairs.

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44
Q

What is the geometry and bond angle of SeO2?

A

Selenium dioxide can form an expanded octet. It forms double bonds with each Oxygen, 120 degrees to each one. It is trigonal planar.

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45
Q

What effect do intermolecular forces have on melting point?

A

The greater intermolecular forces between molecules, the higher the melting point. One of the options was CaCl2, which participates in ionic bonding. These bonds confer extremely high melting points.

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46
Q

What effect does molecule “stacking” (intermolecular forces) have on boiling point?

A

Boiling point is affected by intermolecular forces and molecular weight. The less branching a molecule displays (the more it is like a straight chain), the more easily they can “stack” on each other and produce a higher boiling point

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47
Q

What is the IR signal of the hydroxyl group in an acid?

A

The best way to differentiate an ester and carboxylic acid on an IR signal is the presence of a signal at 3000-3700 cm^-1, which is the acid hydroxyl group

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48
Q

This question is repeated.

A

The pKa occurs at the half equivalence point of the titration curve. This is where pH=pKa and [A-]=[HA].

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49
Q

What effect does a strong reducing agent have on an aldehyde?

A

A strong reducing agent will reduce an aldehyde to a primary alcohol.

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50
Q

What is a thioester? What is a thioketone?

A

A thioester is an ester with a carbonyl oxygen but instead of another oxygen, it is a sulfur. A thioketone has a sulfur instead of an oxygen at the carbonyl oxygen

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51
Q

Take the time to understand chart legends and the axes.

A

If stuck, go back and look at the legends and charts again

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52
Q

What is homotropic regulation? Give an example.

A

Homotropic regulation is when a molecule serves as a substrate for its target enzyme and as a regulatory molecule. Oxygen uses homotropic regulation on Hb, which explains the sigmoidal shape of the affinity graph

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53
Q

What is a positive control?

A

A positive control is one that is not exposed to the experimental treatment, but is know to produce the expected effect being tested. Example-if you are trying to see whethere something inhibits an enzyme, you can use a positive control that is a known inhibitor of the enzyme for comparison

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54
Q

What is the equation for percent dissociation?

A

Percent dissociation = [H+]/[HA-] * 100%. [HA-] is Molarity from given, and then [H+] is form the given pH. Since it was weak acid, you would have to use ICE table and Ka to find pH if not given.

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55
Q

What is the units for Work? What is the work equation?

A

Work is measured in Joules. If a 10 kg object goes from 3m to 0m, the work done is 300 J regardless of if it is on a ramp or not.

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56
Q

What is the equation for energy of a photon?

A

Remember E=hf=hc/wavelength

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57
Q

Passage analysis. Hard question

A

Passage analysis. Hard question

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58
Q

In the ETC, which of the following is a component that is reduced but never oxidized?

A

Oxygen is reduced in the ETC but never oxidized.

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59
Q

In which of the following molecules does the carboxylic acid functional group have the highest Ka?

A

Adding electronegative groups like Flourine to an acid is electron withdrawing, which stabilizes the conjugate base.

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60
Q

A 50kg kid is riding a merry go round. The radius is 5m and the frequency is 0.1 Hz. What is the force required to keep him on the ride?

A

V=(2(pi)r)/T. Use this velocity in F=(mv^2)/r

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61
Q

What is suicide inhibition?

A

Suicide inhibition occurs when it binds irreversibly to the active site.

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62
Q

Double check graph results with answer choice.

A

Double check graph results with answer choice.

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63
Q

What is static friction and what has to happen for the object to overcome it?

A

For static friction, a force is applied until the object moves. While Fapplied is less than its max, the object does NOT move. Fnet = 0 until the object moves.

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64
Q

What is kinetic friction and what has to happen for the object to overcome it?

A

Force is increased until the object moves, which is the force of static friction. Then, force is decreased to maintain a constant velocity, which is the force needed to overcome kinetic friction.

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65
Q

What is the equation for mechanical advantage? What are the dimensions for a 30-60-90 triangle?

A

For an inclined plane, MA=hypotenuse/height. A 30-60-90 triangle has dimensions x, x(root3), and 2x. The MA = 2x/x which is 2.0 MA.

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66
Q

Two objects are placed on a ramp with friction, one is twice as heavy as the other. Which will be more likely to slide down?

A

If two obejcts are on a ramp with friction, their individual masses do not matter in predicting whether they slide down or not. The two objects have an equal likelihood of sliding down.

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67
Q

Air is bubbled through water. The solution will have a pH of?

A

If air is bubbled through water, CO2 can go through hydrolysis to produce carbonic acid, which makes the water more acidic.

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68
Q

What type of compound has a high Rf on a TLC silica plate?

A

On a TLC silica plate, a non-polar compound will have a higher Rf value because the plate is polar and a non-polar substance travels farther. A polar molecule will have polar-polar interactions with the plate and travel slower.

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69
Q

In what direction does polypeptide formation occur?

A

A polypeptide is being formed. The C-terminus is covalently attached to a linker and the N-terminus is free to attach more peptides. Synthesis still proceeds in the DIRECTION of C-terminus to N-terminus.

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70
Q

Assuming a 95% yield for each coupling step, what would be the final yield for synthesizing a 10-amino acid length peptide?

A

If each step is 95% yield and there are 10 steps, the yield is (0.95)^10. This yields around 60% yield.

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71
Q

What is a meso compound? Is it optically active?

A

Meso compounds have multiple chirality centers, but are not optically active overall

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72
Q

Will a product formed from Sn1 attack of a chiral molecule be optically active?

A

If a chiral molecule undergoes Sn1, it will form a racemic mixture and not rotate light at all

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73
Q

What are anomers? What are epimers?

A

Anomers are a specific type of epimer (two molecules that differ about one stereocenter) that have different stereochemistry at the anomeric carbon, which is the atom that serves as the carbonyl carbon in the molecule’s straight chain form

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74
Q

What are diastereomers?

A

Diastereomers are stereoisomers that occur when 2 or more stereoisomers have different configurations at one or more (but not all) of the equivalent stereocenters but are not mirror images of each other. Diastereomers have distinct physical and chemical properties, including bioling point, melting point, and solubility.

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75
Q

What is the difference between staggered and gauche in Newman projections?

A

Staggered is when the substituents on the front carbon are arranged as far away as possible from the substituents on the back carbon. Gauche is when the two largest groups are situated fairly close to each other

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76
Q

Do more trans or cis bonds raise the molecule’s melting temperature?

A

Trans isomers melt at a higher temperature than cis isomers. The trans form can better stack on top of other like molecules, which leads to a higher surface area for intermolecular interactions and raises the melting temperature.

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77
Q

What would happen to ionization energy if Hund’s rule did not apply?

A

The graph showed ionization energies. There is a dip in energy from nitrogen to oxygen due to Hunds rule of spin pairing. If there was no spin pairing, the ionization energy would have continued to increase linearly.

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78
Q

What is Rutherford’s experiment and what did he conclude?

A

Rutherford’s experiment was that alpha particles seemed to pass largely undeflected through a thin gold foil, with occassional rebounding from repulsive forces. Conclusion: most of the volume of a gold nuclei is empty space and alpha particles and the gold nuclei are both positively charged.

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79
Q

What is the effect of gamma rays?

A

Gamma rays generate free radicals, excite electrons to higher energy levels, and eject electrons from molecular orbitals.

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80
Q

What happens to the total mass of a compound after a half life?

A

No matter how many half lives a compound undergoes, the total atomic mass remains the same.

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81
Q

Which type of electromagnetic radiation has the shortest wavelength?

A

Shorter wavelength radiation carries more energy than longer wavelength radiation. The closer an electron is to the nucleus, the harder it is to eject. sp hybridized orbitals have the most s character and their electrons are hardest to eject, but give off the most energy

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82
Q

A person pushes on a 50 kg crate, causing it to accelerate. The the push causes it to accelerate to 2 m/s^2, what is the velocity after being pushed 5 meters?

A

vf^2 = vi^2 + 2ad. 5 m/s^2

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83
Q

What is the hybridization of an imine nitrogen?

A

An imine nitrogen is bound to 2 other atoms and has one lone pair. It is sp2.

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84
Q

Make sure to apply the answer choice interpretation to the graph and see if it makes sense. Also go back and read what the graph is showing in relation to the experiment

A

Make sure to apply the answer choice interpretation to the graph and see if it makes sense. Also go back and read what the graph is showing in relation to the experiment

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85
Q

Be careful with true statements. If stuck between 2 true statements, choose the one that applies more to the experiment concepts

A

Be careful with true statements. If stuck between 2 true statements, choose the one that applies more to the experiment concepts

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86
Q

How does SDS PAGE separate molecules?

A

SDS-PAGE an anionic detergent to the polypeptide chain. Electrophoresis results in fractionation by approximate size lone

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87
Q

How is R/S configuration assigned?

A

R/S configuration priority is assigned based on molecular weight. Make sure the highest priority group is facing towards you, and the lowest (hydrogen) faces away.

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88
Q

What is the pH of a weak acid with pKa of 3.5?

A

The pH of a weak acid must be less than its pKa. If its pH=pKa, that would mean it is a buffer with equal conjugate base and weak acid concentrations. pH must be less than 3.5 but not as low as the pH of a strong acid (1.0)

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89
Q

Make sure to fully understand the graph and its results/implications before answering questions that ask to use the data in a different scenario and predict the outcome

A

Make sure to fully understand the graph and its results/implications before answering questions that ask to use the data in a different scenario and predict the outcome

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90
Q

^same

A

^same

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91
Q

What are “-ate” acids called? What are “-ite” acids called?

A

“-ic” acids have one more oxygen than “-ous” acids. PhosPHATE = “-ic”. PhosphITE = “-ous”

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92
Q

If unsure of what the question is asking about, go back to the passage and try to relate passage concepts/equations to the question

A

If unsure of what the question is asking about, go back to the passage and try to relate passage concepts/equations to the question

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93
Q

How would you find power from PE?

A

PE = mgh. Power units = J/s

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94
Q

What are the energy formulas of a spring if it is perfectly elastic?

A

Perfectly elastic collisions happens when there is no loss of energy and the objects collide but bounce back away from each other. PEspring = (0.5)kx^2. KEspring = (0.5)kx^2. PE=KE

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95
Q

Can you use Celsius in ideal gas laws?

A

For the ideal gas laws, Kelvin must be used.

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96
Q

What is the relationship between electron donating groups and base strength?

A

A base that has electron donating groups via resonance has a more stable conjugate acid. That makes it a stronger base

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97
Q

A slingshot propels a ball at 15m/s from a 30 m tall platform. How far does the ball travel?

A

Formula Deltax = vot + 0.5at^2. Use initial height you are at for deltax. Vo is initially zero. The time is how long the ball is in the air. If you know the time it travels in the air, you can multiply by the horizontal velocity to find distance traveled. Distance = >30 m.

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98
Q

A positively charged particle experiences a force due to an external electric field. Which of the following are conserved? Potential energy, Kinetic energy, Total energy, Momentum?

A

Since the charged particle is experiencing an outside force, only total energy is conserved. Total energy is always conserved

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99
Q

What is the sin of 30 and 60?

A

Sin30 = 0.5. Sin60 = 0.866.

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100
Q

If a weight is being held by two attached cables and youre given the total tension in one of them, how would you find the tension in the other cable?

A

If a box is being held up by 2 cables, the horizontal components of each cable must be equal. Use cosine to find these values.

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101
Q

What is the work done by an object moving in a circle?

A

For an object moving in a circle, the force is towards the center of the circle but the velocity vector is tangential to the circle. The angle between these two makes 90 degrees. Work = Fdcos(theta). If theta is 90, work = 0.

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102
Q

When do you use horizontal and resultant velocity?

A

Make sure to use the resultant (hypotenuse) velocity in the kinetic energy formula. Use horizontal velocity (which is constant) for kinematics

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103
Q

What are the units for Newtons, Joules, and Watts (using kg, m, and s)?

A

A Joule is 1 Nm. A Newton is also (kgm)/s^2. A Watt is 1 J/s. A Joule is also (kg*m^2)/s^2.

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104
Q

A sphere and a hoop of equal mass are both pushed down a frictionless ramp. At the bottom of the ramp, which has the greater translational velocity?

A

An object’s moment of inertia contributes to its rotational kinetic energy. A higher moment of inertia correlates to a higher rotational KE, but a lower translational KE. Since a sphere has more mass concentrated in its center than the hoop, it has a lower moment of inertia and therefore greater translational velocity.

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105
Q

By what factor does period of oscillation in a pendulum change when length is extended from 1 cm to 9 cm?

A

The new period is 3 times larger. The formula for period of oscillation is T = 2pi * sqrt(l/g). If length is increased 9 times, period increases by sqrt(9) or 3 times.

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106
Q

What is the minimum value that velocity can be of a spring after it is stretched and released?

A

The minimum value of velocity of the mass is zero. A mass will reach zero velocity at the extremes of its oscillation.

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107
Q

How would you find the observed force of gravity from a pendulum?

A

A pendulum has a period of T = 2pi sqrt(l/g). You can use the period and length of a pendulum in a non-Earth environment to calculate the new force of gravity in this new place.

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108
Q

If two teams are playing tug-of-war and each side pulls the rope with a force of 100N, what is the tension in the rope?

A

The tension force is 100 N. The tension force is best thought of as the force exerted by the rope on each team. These are a pair of action-reaction forces as depicted in Newton’s 3rd law.

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109
Q

The coefficient of kinetic friction can also equal F(friction) / F(normal). Be careful setting up the friction and forces equation. Force applied - Friction = Actual force felt

A

The coefficient of kinetic friction can also equal F(friction) / F(normal). Be careful setting up the friction and forces equation. Force applied - Friction = Actual force felt

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110
Q

State each of Newton’s laws.

A

Newton’s first law states that objects at rest/in motion stay at rest/in motion until acted upon by an external force. Newton’s second law states that F=ma. Newton’s third law is that for every action, there is an opposite and equal reaction.

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111
Q

Make sure to read every part of the question and try to weed out information that is unnecessary. Compare calculations back to the question before moving on.

A

Make sure to read every part of the question and try to weed out information that is unnecessary. Compare calculations back to the question before moving on.

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112
Q

A buffer solution is acidic (pH = 4). What are potential components of the buffer solution?

A

If a buffer solution is acidic, assume no base is present. Weak acids and the salts (conjugate bases) could be found in the solution

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113
Q

What is the cosine of 0 and 90 degrees?

A

Cosine of 0 degrees = 1. Cosine 90 degrees = 0

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114
Q

What is sound attenuation?

A

Sound attenuation is the weakening of sound signal. It can involve parts of the sound signal being reflected, scattered, absorbed, refracted or diffracted. It would not involve amplification

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115
Q

What is the human range of hearing?

A

The human range of hearing is 20 Hz to 20 kHz.

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116
Q

Conversion of pyruvate into glucose involves enzymes that are located where?

A

Pyruvate conversion to glucose initially involves conversion into oxaloacetate, done by pyruvate carboxylase in the mitochondria. It is then decarboxylated and phosphorylated by PEPCK. It is then transported and the rest of gluconeogenesis occurs in the cytosol.

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117
Q

Glycolysis strongly favors the formation of pyruvate. How is the gluconeogenesis process able to share glycolytic enzymes to create glucose?

A

The formation of PEP, glucose, and F6P push the equilibrium to favor gluconeogenesis because they bypass IRREVERSIBLE steps of glycolysis. This pushes the equilibrium of reversible enzymes used in both glycolysis and gluconeogenesis to favor glucose production

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118
Q

When looking at charts, make sure to remember the experiment and what they are testing for to determine what changes are the cause for certain results. In this question, they measured the absorptivity of the compound. This varied as a result, it was not the cause of the experimental conditions.

A

When looking at charts, make sure to remember the experiment and what they are testing for to determine what changes are the cause for certain results. In this question, they measured the absorptivity of the compound. This varied as a result, it was not the cause of the experimental conditions.

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119
Q

Memorize amino acids

A

Memorize amino acids

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120
Q

Make sure to comprehend the values in the tables and understand their meaning

A

Make sure to comprehend the values in the tables and understand their meaning

121
Q

Be careful assuming causality between charts/experiments. Check that they are measuring the same thing

A

Be careful assuming causality between charts/experiments. Check that they are measuring the same thing

122
Q

What happens to pKb of an aromatic ring after adding a methyl group?

A

Electron donating groups cause an inductive effect. It increases the availability of electron charge density, increasing the strength of the base and decreases pKb.

123
Q

What does amphiprotic mean?

A

Amphiprotic means it can act as either an acid or a base

124
Q

What is the equation for efficiency?

A

Efficiency = W/Qh. Work output/work input

125
Q

What effect does increased efficiency have on work done?

A

Efficiency = work ouput/work input. Increasing this will increase the work (ouput), which increases the area of the graph.

126
Q

What is an imide?

A

Imide is a Nitrogen with 2 Acyl groups bound to it (has two carbons with ketones attached)

127
Q

What do impurities do to the melting point range?

A

The presence of impurities would lower and broaden the melting point range.

128
Q

What factors affect a TLC plate retention factor? Compare Rfs between polar and nonpolar compounds. What is eluting strength?

A

Rf depends on the solvent system, temperature, and adsorbent. Polar compounds have smaller Rfs because the plate itself is polar and they travel less distance than nonpolar compounds. Eluting strength is how strongly the compound adsorbs into the adsorbent. Adsorbents are typically highly polar, so eluting strength increases with increasing solvent polarity. Ex-methanol is more polar than pentane and so has a greater eluting strength

129
Q

What is the normality of 0.015M phosphoric acid?

A

Phosphate is PO4(-3). Phosphoric acid is H3PO4. Multiply by 3 for normality. 0.045 N.

130
Q

What is an aromatic ring?

A

Aromatic rings have 4n+2 pi electrons, where n is number of double bonds.

131
Q

Compare fetal and maternal hemoglobin?

A

Fetal hemoglobin has a greater affinity for oxygen than maternal hemoglobin.

132
Q

How do you read graphs with 2 y axes?

A

Pay close to attention to units. If there are two lines, make sure to find the line associated with the units in question. In this example they found the point on that line and then used the x axis value to answer it.

133
Q

A large steel water storage tank with a diameter of 20 m is filled with water and is open to the atmosphere (1 atm = 101 kPa) at the top of the tank. If a small hole rusts through the side of the tank, 5.0 m below the surface of the water and 20.0 m above the ground, assuming wind resistance and friction between the water and steel are not significant factors, how far from the base of the tank will the water hit the ground?

A

Use Bernoulli’s equation to find velocity of water coming out. P1 + pgy1 + 0.5pv1^2 = P2 + pgy2 + 0.5pv2^2. The entire left side is zero. Solve for velocity which is 10 m/s. Use kinematics equation d = vit + 0.5gt^2. Find time. T = 2 seconds. 10 m/s traveled for 2 seconds = 20m.

134
Q

What are reducing sugars?

A

Reducing sugars have hemiacetal groups. A terminal carbon is connected to another carbon, a hydrogen, an -OH group, and an -OR group. Acetals have 2 -OR groups.

135
Q

How can you reduce the carboxylic acid of a compound that has a carboxylic acid and a carbonyl group? (Using LiAlH4)

A

LiAlH4 is capable of reducing both groups. You can treat the compound with alcohol to form an acetal group on the carbonyl. This would not be affected by the LiAlH4, which would then only reduce the carboxylic acid. You can easily remove the acetal with acidic conditions.

136
Q

CoQ is a ring with two ketones. It is usually reduced with 2 electrons, but what would happen if it was only reduced with 1 electron?

A

It would form a free radical. The pi electrons from the ketone will be transferred into the ring, creating one alcohol group. The other oxygen would still accept those pi electrons that were pushed into the ring and it would have 5 valence electrons, forming a radical.

137
Q

What is the mechanism to convert a carboxylic acid into an amide?

A

First, create an acid chloride or acid anhydride to eliminate the acidic hydrogen on the acid. From here, do nucleophilic substitution with an amino substituent.

138
Q

Addition of which type of amino acid would most disrupt sodium hydroxide’s ability to induce a saponification reaction? Leucine, Valine, Proline, Arginine?

A

The hydroxide ion acts as a nucleophile and a base. Therefore, we want an amino acid that is also a strong nucleophile or neutralizes the base. Arginine would be deprotonated by NaOH.

139
Q

How do you find rate law from experimental data?

A

Identify two trials where only one reactant concentration changes. If the concentration changes the same number of times as the rate, the rate is 1. Example: concentration goes from 0.10 to 0.15 and rate goes from 0.20 to 0.30. They both increase by 1.5 times. The rate law would be 1. If one doubles and the other quadruples, the rate law is 4.

140
Q

Reaction 1 has an enthalpy change of -188. Reaction 2 is the backwards reaction, but with a stoichiometric coefficient of 2 in front of the compounds. What is the enthalpy change of reaction 2?

A

The reverse reaction has an enthalpy change of +188. The stroichiometric coefficients make it double, so its +377.

141
Q

In a redox reaction, you want silver to precipitate on to the plate. The half reaction is Ag+ + e- -> Ag +0.80E. What is the reduction potential?

A

Silver precipitation means silver is being reduced. E would be 0.80. Since E is positive, the Delta G is negative and it is spontaneous (DeltaG = -nFE)

142
Q

What is the value of Keq under standard conditions?

A

At standard conditions, Keq = Q. Remember QK goes backwards (direction of arrow shows which way reaction proceeds)

143
Q

What is the voltage generated by an electrochemical cell at equilibrium?

A

At equilibrium Delta G is zero. Therefore redox potential is also zero and voltage is zero.

144
Q

What is a Bronsted Lowry base?

A

A proton acceptor

145
Q

What is the ground state electron configuration of Co+?

A

During ionization of transition metals, electrons from the higher energy 4s orbital are removed before electrons in the 3d orbital. Answer is 3d7

146
Q

Which of the following can NOT be oxidized? H2S, SO4(2-), S8, S2O3(-)

A

The highest oxidation state of sulfur is +6. Here it has lost all valence electrons. In SO4(2-), the Sulfur has an oxidation state of +6, so it can not be possibly oxidized anymore

147
Q

Study H NMR

A

Study H NMR

148
Q

Which elements undergo hydrogen bonding?

A

F-H, O-H, N-H

149
Q

What happens to boiling point when soluble, nonvolatile solutes are added to a liquid?

A

Boiling point increases

150
Q

What is the molecular shape of the hydrogen compounds of the main group elements with 5 valence electrons?

A

Think NH3….trigonal pyramidal.

151
Q

What kind of compound is more likely to undergo beta (+) decay? (hint: think about what kind of molecule is emitted here vs in beta (-) decay)

A

A compound with an excess of protons, because it emits a positron. Alpha (-) decay would be more likely in compounds with an excess of neutrons, since they emit an electron

152
Q

What describes the velocity profile of laminar flow?

A

Fluid velocities closer to the tube are slower due to friction, and fluid velocities closer to the middle of the tube are faster. It creates a gradient of velocities.

153
Q

If a blood vessel’s radius increases by 10%, by how much will the volume flow rate change?

A

Q = [pir^4DeltaP]/[8viscosityL]. Flow rate is directly proportional to radius raised to the 4th power, so it will increase by 150%.

154
Q

What will be the difference in hematocrit between a person that lives in higher elevation and a person at low elevation?

A

The person at higher elevation will have a higher hematocrit. Their bodies are making more red blood cells because there is less oxygen in the air.

155
Q

Make sure to look at the equations given in the passage for calculation questions

A

Make sure to look at the equations given in the passage for calculation questions

156
Q

A horizontal force of 100N is applied to a 50kg box. It accelerates at 1 m/s^2 on a rough surface. What is the work done by kinetic friction if it is moved 4m?

A

Total work = Fapplied - Ffriction. (50)(1m/s^2) = 100N - Ffriction. Ffriction = 50N. Work = 504 = 200 J.

157
Q

2 detectors have a 5V potential difference between them and are separated by 3 cm. What is the magnitude of the electric field and what are the units?

A

The units for electric field are V/m. 1 V = 1 J/C, so electric field is also N/C. The answer is approx 160 N/C.

158
Q

Destructive interference occurs when light rays differ in phase by how many degrees?

A

180

159
Q

If calculation is not extremely close to an answer choice, read question again before choosing an estimate

A

If calculation is not extremely close to an answer choice, read question again before choosing an estimate

160
Q

What kind of wave has a shorter period?

A

One with a shorter wavelength

161
Q

What is the difference between waves that are in phase and waves with zero displacement?

A

Zero displacement happens when they cross the x axis. Waves that are in phase means constructive interference: simultaneous peaks and parallel lines, if not totally identical and on top of each other

162
Q

What is the relationship between wave harmonic and frequency?

A

As you increase the harmonic number, there is a shorter period and thus higher frequency.

163
Q

Compare all graphs to each other before guessing

A

Compare all graphs to each other before guessing

164
Q

A jet is traveling 300 m/s away from a stationary receiver. Another jet travels 600 m/s past another receiver. How fast and in what direction would that receiver have to go to get the same change in frequency?

A

The new receiver would have to go 300 m/s towards the 600 m/s jet to result in the same 300 m/s relative velocity and the same change in frequency

165
Q

If the graph axes and chart data titles are identical, you can assume that they are related.

A

If the graph axes and chart data titles are identical, you can assume that they are related.

166
Q

What is the Doppler effect and equation? What happens to wavelength as oberserver speed away from the source is increased?

A

The Doppler effect says that as the observer gets farther away the wavelength increases. The equation is observer /source. If observer is traveling away, it is a bigger number on top and negative so the numerator decreases which decreases perceived frequency

167
Q

Why are changes in frequency and wavelength greater when sound waves are used as compared to radio waves?

A

Because the velocity of sound is lower than the velocity in electromagnetic radiation (radio waves)

168
Q

Wavelength of a star is found to be higher in the lab than the wavelength measured. What explains the discrepancy? (doppler effect)

A

The star (source) is moving towards Earth.

169
Q

An ice cube is 9/10 submerged in a glass of water on earth. On the moon, how much would be submerged?

A

Still 9/10 since the bouyant force is proportional to gravity, but gravity’s numerical value is irrelevant

170
Q

What happens in reflection?

A

n goes from a higher to lower value. Angle of incidence is greater than the angle of refraction. The incoming beam (after going through the medium) will have the same angle as the angle of incidence

171
Q

A sample of metal is held exactly at its melting point. If a bunsen burner right under it is lit for a split second, what happens?

A

A small amount of metal melts but temperature remains the same. Temperature of the sample does not increase until all the metal is melted.

172
Q

What happens to a charged particle in an electric field?

A

It accelerates towards the opposite pole

173
Q

When do gases behave least ideally?

A

Under high pressure and low temperature, which are conditions that would most favor the formation of a liquid

174
Q

What assumptions are necessary for the ideal gas law to work properly?

A

Particle volume is negligible and there are no intermolecular forces present

175
Q

What changes/stays the same as light passes from air to another medium?

A

Speed of light does change when moving between materials with different indexes of refraction. It would decrease going into a higher index. Frequency is constant because E=hf and energy can not be lost. If velocity decreases and frequency is constant, wavelength must also decrease

176
Q

What happens if a doppler ultrasound device is held at exactly 90 degrees to a blood vessel?

A

Since the blood is not moving away or towards the device, there is no doppler shift and frequency remains the same

177
Q

What is the equation for wavelength of an open pipe vs. a closed end pipe?

A

Open = 2L/n. Closed = 4L/n. n is harmonic number and closed pipes only have odd harmonics

178
Q

What is the equation for sound velocity through a metal?

A

v = sqrt(B/density), where B is the bulk modulus. A denser metal makes sound travel slower

179
Q

State the light spectrum

A

Decreasing wavelength (increasing frequency): radio, infrared, (780nm) ROYGBIV (380nm), UV rays, X rays, gamma rays

180
Q

What is the relationship between light color and index of refraction?

A

Light with longer wavelength (red) will have the smallest index of refraction and bend the least when moving from vacuum to a prism

181
Q

Light with 640 nm wavelength is directed onto a screen with two slits. The researcher measures from one bright band to another. What is the distance between the bands?

A

Since there is constructive interference, the waves must be completely in phase or differ by a multiple of the wavelength. The distance could be 640, 1280, 1920, etc.

182
Q

What changes occur when visible light moves from a low index to high index medium?

A

The equation for index is n = c / v. The light will slow down as index increases. Since velocity slows down and frequency is always constant, then wavelength must decrease

183
Q

For a ray that contacts a flat surface, what is the angle of reflection?

A

The angle of reflection is equal to the angle of incidence.

184
Q

What happens to light going from a low index to high index?

A

The ray bends towards the normal, so the angle of refraction is less. Light would travel slower in the higher index material. It is NOT internal reflection, which happens only going from high index to low index and angle of incidence is large

185
Q

What is the critical angle?

A

The angle of incidence above which total internal reflection will occur. It yields an angle of refraction of 90 degrees.

186
Q

What type of mirror has a positive focal length?

A

Positive focal lengths mean it is a converging mirror, which is concave. Converging lenses are convex, diverging lenses are concave

187
Q

What type of lens fixes myopia?

A

Myopia is excessive convergence, so diverging lenses would fix it

188
Q

What are the charged amino acids at neutral pH?

A

Lysine and Arginine are positive, Glutamic acid and Aspartic acid are negative.

189
Q

What is the fisher notation for glucose?

A

Carbons 2-5: Right, Left, Right, Right. (R,S,R,R). In the ring (the three carbons with OH), it is down up down from left to right.

190
Q

A foam raft has a density of 490 kg/m^3. In water, what percent sticks above the surface?

A

Specific gravity = density of object/density of water. Density of water is 1000 kg/m^3. So, the specific gravity is 0.491 and 49.1% is submerged. Therefore, 50.1% is sticking out above the water.

191
Q

What does a specific gravity greater than 1 tell you?

A

The object will sink

192
Q

What is the density of water?

A

1000 kg/m^3, 1 g/cm^3, 1 g/mL, or 1 kg/L.

193
Q

An element prefers to form one bond and possess 3 lone pairs. Which group is it from?

A

This element has seven valence electrons: one in the bond and six in lone pairs. It is from Group 17

194
Q

What is the ionization energy trend? What is the exception?

A

IE increases going up and to the right. Nitrogen is an exception because its electron configuration is 2s2 2p3, which means losing another electron would disrupt the half filled p orbital and the full s orbitals. Ionizing Oxygen, which is 2s2 2p4, results in half filled p orbitals, which is very favorable. So oxygen has a lower IE than nitrogen. (IE is the element’s willingness to lose an electron)

195
Q

Is an alkali metal more likely to be oxidized or reduced?

A

Because it is all the way to the left on the table, it has a low ionization energy making it easy to lose an electron

196
Q

What is the electron configuration of Os 3+?

A

Remember that for cations, the highest energy electrons are removed first. Electrons in the 6s orbital are removed first. The answer is 4f14 5d5.

197
Q

What quantum number denotes subshell and angular momentum?

A

l, the azimuthal number. It shows whether it is found in an s, p, d, or f subshell. The magnetic number, m, narrows down location to an orbital within a subshell.

198
Q

What is Faraday’s constant?

A

1 mole e- = 96500 C. Charge of an e- = 1.60 * 10^-19.

199
Q

Malic acid is dehydrated to form fumaric acid and maleic acid. Is the reaction stereospecific?

A

No, because the fact that both are produced from the reaciton means that the reaction is not stereospecific, or it does not preferentially produce a particular stereoisomer of the product

200
Q

What is eye focal length?

A

The strength of an eye lens is the inverse of the focal length, which is also 1/i + 1/o.

201
Q

What would decrease the percentage ionization of an aqueous solution of acetic acid?

A

Adding concentrated HCl will increase the amount of H+ ions in the solution, which decreases the amount of acetic acid that ionizes.

202
Q

What is the index of refraction equation?

A

n = c / v, where c is speed of light.

203
Q

A compound undergoes oxidation and spontaneous micellular assembly to form another compound. What type of interactions make it stronger than it was originally?

A

Intermolecular covalent bonding. It is intermolecular because multiple molecules of this compound come together to form the micelle. It is covalent bonding because the oxidation points to disulfide bridges being formed

204
Q

What is the source of phosphate groups that are added in kinase activity?

A

Phosphates come from ATP, the kinse just uses ATP phosphate to transfer it.

205
Q

Make sure to double check what is being asked for in calculation questions

A

Make sure to double check what is being asked for in calculation questions

206
Q

What types of bonds are made by glycogen synthase?

A

Alpha 1,4-glycosidic bond.

207
Q

For questions that ask about the effect of something talked about in the passage, make sure to read about what exactly it does and compare that to the normal condition

A

For questions that ask about the effect of something talked about in the passage, make sure to read about what exactly it does and compare that to the normal condition

208
Q

Comparing H2PO4(2-) and H3PO4, which one will dissociate less?

A

H2PO4(2-) will dissociate less due to the high negative charge.

209
Q

Gamma decay occurs when a nucleus emits?

A

Gamma decay is emission of photons by the nucleus.

210
Q

What happens if NaCrO4 is added to a saturated solution of BaCrO4? (Dissociation: BaCrO4 Ba (2+) + CrO4 (2-)?

A

It would shift equilibrium left. Adding this introduces the common ion CrO4(-2), which reduces solubility of BaCrO4.

211
Q

What are the units of power?

A

W = J/s = kgm^2/s^3 = ftlb/s

212
Q

What is the ksp expression of lead iodide? How do you know if it is soluble?

A

Ksp = [Pb(+2)] [I(-)]^2. Plugging in the molarity for each one and multiplying yields the Q, or ion product. If Q

213
Q

What happens if you add an anion to this equation: CaC2O4 -> Ca(2+) + C2O4(-2)? Hint: the anion binds to Calcium and forms a precipitate

A

When calcium precipitates out of the system, the equilibrium shifts right (Le Chatelier’s) and the system is forced to regenerate more Ca and C2O4 ion

214
Q

If molar solubility of AgCl is 2*10^-5, what is its Ksp?

A

The Ksp expression is [Ag] [Cl]. Give molar solubility the variable “x”. This translates to a Ksp expression of x^2 due to the 1:1 molar ration. (210^-5)^2 is 410^-10.

215
Q

What is the difference between Lewis and Bronsted Lowry acids/bases?

A

The Lewis definition involves a transfer of electrons associated with the formation of a bond. The Bronsted Lowry definition involves the movement of a proton from one molecule to another. When trying to find Lewis acid/base, look for compounds that are donating their electrons (Lewis base) to another species (Lewis acid). A cation is an easy way to spot a Lewis acid because cations readily accept electrons.

216
Q

What is the relationship between Ka, Kb, and the pka/pkb?

A

Larger Ka’s mean stronger acids and larger Kb’s mean stronger bases. Stronger acids and bases have lower pka’s and pkb’s.

217
Q

What are the effects of electron donating groups?

A

Electron donating groups make an acid weaker by destabilizing the conjugate base. The stability of the conjugate is most influenced by resonance and electron withdrawing groups.

218
Q

What is electron affinity? What direction does the trend point to?

A

High electron affinity means the element is likely to act as an electron acceptor. The trend increases going towards Helium, up and to the right

219
Q

What prediction can be made about the conversion of N2 gas into solid Nitrogen?

A

Entropy decreases and Delta S is negative.

220
Q

Would there be significant ideal gas law deviations present in a gas that is held at 180 GPa and room temperature?

A

Yes, because at this extremely high pressure, molecular volumes and IM forces become significant. At this high pressure the solid form is favored.

221
Q

What is the frequency of a spring system?

A

f = (1/2pi) * sqrt(k/m).

222
Q

What happens when an acid and its conjugate base are present in solution in equal concentrations?

A

The pH will be equal to the pKa of the acid.

223
Q

What is the difference between electron affinity and ionization potential?

A

Electron affinity is the amount of energy released or spent when an electron is added. Ionization potential is the energy required to remove an electron. A small ionization potential means it will readily lose the electrons and react. The reactivity of a metal depends on its ionization potential

224
Q

What happens in an electrolytic cell?

A

These are non spontaneous, meaning external current is used to promote the reaction. In this case, make sure that the potentials are backwards: the metal with the more negative reduction potential, which is usually oxidized, becomes reduced. Flip the sign of the other one in this case. A good hint is that Delta G must be positive becaue it is non spontaneous. Reduction still happens at the cathode and oxidation at the anode: this is always true

225
Q

What is a galvanic cell?

A

This includes rechargeable batteries. These are spontaneous processes that release stored energy. Remember, Delta G must be negative here so E has to be positive. The cathode is still the site of reduction and the anode is the site of oxidation: this is always true

226
Q

Compare the charges of anode/cathode in electrolytic vs. galvanic cells?

A

Since galvanic cells are spontaneous and electrons ALWAYS flow from anode to cathode, so the anode here must be negative and the cathode is positive. Electrolytic cells are nonspontaneous and also have electrons flowing from anode to cathode, but they have positive anodes and negative cathodes.

227
Q

How does electrostatic force change when the dielectric constant is increased? What if the distance was doubled between the two charges?

A

Use the equation F = k (Qq/r^2). If r is doubled, the force is reduced by 1/4. The k constant is Coloumb’s constant which is equal to 1/(4pidielectric constant). Increasing the dielectric constant will reduce the force.

228
Q

What is an electron volt, eV?

A

The amount of energy required to move one electron through a one volt potential.

229
Q

What equation shows the force that a charge experiences when placed at a point in an electric field?

A

F = qE (similar to F = ma).

230
Q

If a circuit has 2 resistors in parallel, what is the same between them?

A

Voltage drop across them is the same, but current may be different. If they were in series, the current is the same but the voltage drop in each of them may be different.

231
Q

Will current flow to a branch with a resistor or capacitor?

A

A capacitor, because current tends to flow towards the path of least resistance and capacitors have virtually no resistance. Once the capacitor is fully charged after some time has passed, additional charge is unable to build up on it and current is blocked from passing through it

232
Q

How do you find voltage drop in a complex circuit?

A

First find the total resistance from adding all the branches. The voltage drop is between two points. Find the total resistance between these two points, and then multiply it as a fraction. Example-the branches in this problem added up to 2 ohms, when the total circuit was 15. So for voltage drop of these branches, do 2/15 * V.

233
Q

What is the capacitance equation?

A

C = dielectric constant * A/d.

234
Q

What is the resistance of a circuit (not V=IR)?

A

R = p * L/A (The “replay” formula)

235
Q

What is the equation for magnetic force?

A

F = qvB. This shows a particle must possess both velocity and a charge to be affected by the magnetic field. Magnetic force always exerts a force on a moving particle that is perpendicular to both the particle’s velocity and field itself. If the force is exerted parallel to the object’s motion and contributes to it moving in that direction, no work is done. (W = Fdcos(theta))

236
Q

An electron is moving towards the right and is held in equilibrium by gravity and an external magnetic field. Which way does the field point?

A

Right hand rule: thumb goes to the right and palm is upwards because it must oppose gravity. From here, fingers point into the page BUT the right hand rule is for positive charges, so flip it for an electron. The field points out of the page

237
Q

What is the cosine of 60?

A

1/2

238
Q

Be careful with least questions

A

Be careful with least questions

239
Q

What is the equation for rate of effusion?

A

The root mean square speedis Vrms = sqrt[(3RT)/M]

240
Q

What amino acid residues are more likely to undergo phosphorylation?

A

Serine, threonine, tyrosine, and histidine.

241
Q

What is the hybdridization of [Mo (CO)6]? sp3d2 or d2sp3?

A

sp3d2 hybridization means that all the orbitals have the same principal quantum number. d2sp3 hybridization means that the principal quantumnumber of the d orbitals is one less than the s and p orbitals. d2sp3 occurs in transition metals and sp3d2 occurs in nonmetals.

242
Q

What kind of reaction is involved in proteolysis, the breakdown of proteins?

A

Hydrolysis reactions

243
Q

What happens in a lens where a material is used that is strongly dependent on the wavelength of transmitted light?

A

If transmitted light rays refracted differently based on their wavelengths, then the focal lengthof the lens differs for each wavelength of light. For any light with rays of multiple wavelengths, the rays would focus at multiple points and result in an unfocused image. This is called chromatic aberration, where optical instruments fail to converge light rays from a source to a single point.

244
Q

How do you find number of possible stereoisomers?

A

Calculating the number of stereoisomers is 2^n, where n is number of stereocenters. Be careful that the other stereoisomer is not also meso, because this would only count once and so you subtract the number of stereoisomers by one.

245
Q

In an isolated system, when is entropy maximized?

A

At equilibrium and when the system is unable to perform work. When at equilibrium, Delta G = 0. At this point there are no energy gradients so energy is maximally dispersed throughout the system, resulting in max entropy. At equilibrium, the system cannot perform work.

246
Q

What is a stereoselective reagent?

A

These are chiral reagents that can react with another molecule and produce enantiomers. Achiral reagents are not included here because they dont produce enantiomers

247
Q

What kind of reagent is aluminum hydride?

A

It is a powerful reducing agent. When trying to predict which part of the molecule gets reduced, look for the most highly oxidized portion. This molecule had a double bond and 2 hydroxyl groups, so it would have reduced the double bond

248
Q

If lost on a passage, briefly look at charts and compare to the results given in answer chocies.

A

If lost on a passage, briefly look at charts and compare to the results given in answer chocies.

249
Q

How is acidity determined (ina ring)?

A

Acidity is determined by the stability of the conjugate base. The stronger conjugate base means the acid is stronger. In a benzene ring, the delocalized p orbitals from the ring are what help stabilize the anionic conjugate base.

250
Q

What is non competitive inhibition?

A

Km is unchaged but Vmax is decreased. The competitor binds to an external site and alters the enzyme conformation. Uncompetitive inhibition binds the ES complex, but both Km and Vmax are affected.

251
Q

What is the conversion for amps?

A

1 Amp = 1 C/s. There is 96500 C per mole.

252
Q

In an electrolytic cell, where do electrons flow into solution?

A

In an electrolytic cell, the anode is positively charged and the cathode is negatively charged. Electrons flow from anode to cathode, but this question asks where do electrons flow into solution. This would be the site of reduction, so at the negatively charged cathode.

253
Q

If the question is vague, look back at passage reactions for guidance or hints about the type of species or reaction they are looking for.

A

If the question is vague, look back at passage reactions for guidance or hints about the type of species or reaction they are looking for.

254
Q

If they ask which has the smallest atomic radius between species that are all isoelectronic, which one is smallest?

A

Look for the species with the most protons, because they would pull electrons furthest in.Dont get caught up in the ion charges.

255
Q

What are the units for 1st, 2nd, and 3rd order rate laws?

A

1st: s^-1. 2nd: L mol^-1 s^-1. 3rd: L^2 mol^-2 s^-1. If in doubt, find it with k * (mol/L)^order. k = M/s. Multiply together and cancel out terms.

256
Q

What are vector quantities? What are scalar quantities?

A

Displacement and velocity are vectors because they both have direction and magnitude. Distance and speed are scalars because they only convey magnitude. Remember, displacement is the shortest distance between two points and is not always the same as distance traveled (think of someone walking in a circle and their displacement/distance traveled)

257
Q

What are the sines and cosines of 30, 45, 60, 90?

A

Sin30 = 0.5. Sin45 = 0.71. Sin60 = 0.866. Sin90 = 1. || Cos30 = 0.866. Cos45 = 0.71. Cos60 = 0.5. Cos90 = 0.

258
Q

What forces are conserved as an object falls in a gravitational field?

A

Only total energy is conserved. KE and PE will change throughout the fall. Think of a projectile thrown upward: KE changes as it goes up and comes back down. Same with PE. Momentum is not conserved, as velocity will change

259
Q

What is the equation for gravity? If a planet has twice the radius as earth, what is the magnitude of its gravity?

A

F = (Gm1m2)/r^2. If radius is doubled, the force of gravity decreases by a factor of 4.

260
Q

What are the kinematics equations?

A

d = 0.5(v0 + v)t. d = vot + 0.5at^2. v = vo + at. v^2 = vo^2 + 2ad.

261
Q

What does a low vapor pressure imply about boiling point?

A

Low vapor pressure corresponds to high boiling point

262
Q

What is impulse?

A

Impulse is the change in momentum. It has the units Ns, or (kgm)/s

263
Q

What is the formula for centripetal acceleration?

A

Fc = mv/r^2

264
Q

What are reducing sugars?

A

They have a hemi acetal group at the end. Glucose and fructose are reducing sugars. sucrose is not.

265
Q

In reverse phase high performance liquid chromatography, what elutes first?

A

This includes a polar mobile phase and non polar stationary phase. The more polar compound elutes first.

266
Q

Convert 1 m^3 to cm^3

A

1m^3 = 10^6 cm^3. Remember, in 10^x the number of the exponent will equal the total number of zeroes in the number. Example: 10^6 = 1,000,000

267
Q

What does the principal quantum number estimate?

A

It is most closely associated with the potential energy of the electron. It is also associated with the radial “size” of the electron cloud.

268
Q

Where does C=O stretching occur in IR?

A

1700-1750 cm^-1

269
Q

How can 2 achiral compounds react to form a stereospecific compound?

A

The stereospecificity can only be explained by a chiral enzyme

270
Q

If a speaker emitting a sound wave is thrown into the air, what is the detected wavelength when it reaches the highest point above the ground?

A

At the largest height, the projectile has stopped moving. As a result, there is no Doppler shift. In this case, the frequency shift is negative as it travels upwards and hits zero at the peak. On the way down, the frequency shift becomes increasingly positive

271
Q

What is a nitrile?

A

A carbon triple bonded to a nitrogen

272
Q

What effect does a competitive inhibitor have?

A

Decrease Km and Vmax is unchanged

273
Q

What is a furan?

A

A furan is a 5 membered ring that is aromatic with 4 carbons and 1 oxygen

274
Q

What is the difference between reaction coordinates that show exergonic vs endergonic and exothermic vs endothermic?

A

Reaction coordinates are graphs that show the course of the reaction with the activation energy and the hump of the transition state. Make sure that they tell you the change in energy is due to a transfer of heat. Otherwise if it is just a change in energy, it would be exergonic or endergonic. According to google, exergonic graphs can have axes with both free energy or potential energy, and exothermic graphs have axes with potential energy too

275
Q

If unsure about how many electrons are transferred in an electrolytic/galvanic cell, look at the equations and find the oxidation states to calculate the number of electrons transferred

A

If unsure about how many electrons are transferred in an electrolytic/galvanic cell, look at the equations and find the oxidation states to calculate the number of electrons transferred

276
Q

What is the bond order of the bond to oxygen in Glycine at pH 7?

A

At neutral pH, the carboxyl group is deprotonated and the negative charge is delocalized by resonance. The bond order is 1.5 due to resonance.

277
Q

If the graph has a p value greater than 0.05, then any observed relationship between the variables could be due to chance.

A

If the graph has a p value greater than 0.05, then any observed relationship between the variables could be due to chance.

278
Q

What is the cos90?

A

Cos90 is 0. In the Doppler effect, readings become less accurate as the cos theta approaches zero, meaning it is less accurate when the doppler machine is at a 90 degree angle to the blood flow

279
Q

What is a transverse wave?

A

Transverse waves include electromagnetic waves, like visible light, that can travel through a vacuum. Longitudinal waves cannot travel in a vacuum because they need to propagate through a compressible medium. Sound waves are longitudinal

280
Q

How do you separate enantiomers?

A

The only way to separate enantiomers in a racemic mixture is to use substances that interact differently with each enantiomer. We have to introduce one or more chiral compounds that can be associated in a stationary phase. One way to do this is chiral resolution

281
Q

What is size exclusion chromatography?

A

Smaller particles become trapped in the pore system present in the agarose stationary phase, while larger particles pass directly through. So, smaller particles migrate more slowly. Remember, in electrophoresis molecules move more rapidly than larger ones.

282
Q

What type of compounds are present in a mixture of NH3 and BF3?

A

NH3 has a lone pair that readily accepts protons to form NH4+. It is a BL base. Since BF3 does not have any protons to donate, it is neither

283
Q

What is a Lewis acid?

A

An electron acceptor. If lost, look for passage hints like an atom “gaining a negative charge” in the reaction.

284
Q

What happens to entropy when non polar (hydrophobic) molecules are immersed in aqueous solution?

A

In an aqueous solution, exposed non polar molecules cause water molecules to form an ordered structure called the solvation layer. There is a resulting large decrease in entropy (disorder) of the water because it is more organized as part of the solvation layer interactions. In contrast, the hydrophilic region mixes well with water and forms a less ordered solvation layer, so the entropy change is less negative. In summary, polar regions like to face the watery environment and promote a less negative change in entropy than would the non polar regions.

285
Q

What happens in a blood vessel that becomes constricted?

A

When the vessel narrows, the fluid’s velocity increases based on the A1v1 = A2v2 equation. As a result, hydrostatic pressure decreases to conserve energy. Hydrostatic pressure is the pressure exerted by the fluid.

286
Q

What is the intensity equation?

A

Decibels = 10log(I/Io), where Io is the reference intensity which is the lowest intensity that humans can hear. Intensity = Power/Area. So if power increased 100 times, then area must also increase 100 times to maintain the intensity.

287
Q

What is the abscissa and ordinate?

A

The abscissa is the x axis and the ordinate is the y axis

288
Q

What happens when light goes to high index of refraction to lower index of refraction?

A

It bends away from the normal

289
Q

Why is a carbonyl group electronegative?

A

The electronegativity difference between the carbon and oxygen results in the oxygen withdrawing electron density from the carbon and leaving it with a partial positive charge

290
Q

What is the advantage of vacuum distillation over simple distillation?

A

Vacuum distillation facilitates the separation of compounds with extremely high BP’s. Remember, compounds boil when their vapor pressure = ambient pressure. Adding a vacuum lowers ambient pressure and makes compounds with high BP’s easier to boil

291
Q

What is recrystallization?

A

Removing impurities from solid samples. Choose a solvent that the compound is relatively soluble in at warm temperatures and insoluble at cold temperatures. So we can heat it up to dissolve the mixture, and then recrystallize it when it is cooled so that only the compound crashes out and impurities are still dissolved

292
Q

Compare the NMR spectrum of a methyl hydrogen and an aldehyde hydrogen

A

The aldehyde H is closer to the electron withdrawing carbonyl, so it is in a zone of electron deficiency. It is more exposed to the NMR device because of a decrease in shielding causing a shift to the left on the spectrum

293
Q

What does NMR measure?

A

It bends away from the normal

294
Q

What strand of DNA is transcribed?

A

The electronegativity difference between the carbon and oxygen results in the oxygen withdrawing electron density from the carbon and leaving it with a partial positive charge

295
Q

What is required for PCR?

A

Vacuum distillation facilitates the separation of compounds with extremely high BP’s. Remember, compounds boil when their vapor pressure = ambient pressure. Adding a vacuum lowers ambient pressure and makes compounds with high BP’s easier to boil

296
Q

What happens to a molecule that absorbs UV light?

A

Removing impurities from solid samples. Choose a solvent that the compound is relatively soluble in at warm temperatures and insoluble at cold temperatures. So we can heat it up to dissolve the mixture, and then recrystallize it when it is cooled so that only the compound crashes out and impurities are still dissolved

297
Q

What are storage lipids?

A

The aldehyde H is closer to the electron withdrawing carbonyl, so it is in a zone of electron deficiency. It is more exposed to the NMR device because of a decrease in shielding causing a shift to the left on the spectrum

298
Q

What is an acetyl group?

A

Adding a CH3C=O

Alex Deleon’s MCAT Flashcards (6 decks)

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