MCAT Chemistry and Physics Flashcards
1
Q
What is the meaning of isoelectronic?
A
Isoelectronic = having the same numbers of e- or the same electronic structure.
2
Q
What sides are multiplied when using the sine?
A
Multiply the opposite side from the angle and the hypotenuse
3
Q
What does the slope of a displacement vs. time graph represent?
A
In a displacement vs. time graph, the slope of the graph correlates to the velocity of the object
4
Q
What big four kinematics equation should you use if the missing variable is time?
A
Vf^2 = Vi^2 + 2ad
5
Q
What two kinematics equations can be used to solve for distance when given a free fall problem?
A
- y = 1/2 * gt^2 2. t = (2y / g) ^ (1/2)
6
Q
What is the exception to Aufbau rules?
A
Exception to Aufbau rule: e- should be removed from a higher orbital in order to achieve a more stable state. (i.e. Mn ^2+ should have e- removed from 4s^2 before 3d^5)
7
Q
What is ionization energy?
A
Ionization energy refers to amount of energy to remove an e-
8
Q
What is the function of phosphorus in fluorescent lights?
A
Phosphor essentially acts to convert the ultraviolet light emitted by mercury into light waves in the visible range.
9
Q
What equation is used to determine energy when given wavelength?
A
Use equation: E = (h*c)/ lambda h = 6.63 *10^-34 m^2kg/s
10
Q
What equations are needed to find the end height of an object when given the following: distance, Vi, and angle of launch from the horizontal?
A
Find time it takes to travel sed distacne by breaking down Vi into Vx and Vy. Equation: Vx = Vicos(angle) and Vy =Visin(angle) Then use (yi - yf) = Vyt + (1/2)a*t^2
11
Q
What is (arguably) the strongest intermolecular forces?
A
Hydrogen bonding
12
Q
What is the primary factor in determining bond length?
A
Bond lenght is primarily determined by the atomic radii of the bonded atoms. So, bonds formed with hydrogen atoms tend to be shorter than bonds formed with any other atom.
13
Q
What is a dipole moment?
A
The polarity that exists between two molecules. Often represented by an arrow with a plus sign near the atom with the partial +, pointing in the direction that the e- are being pulled (towards the more electronegative atom.
14
Q
What are the bond angles in an ideal tetrahedral geometry?
A
They are equal to 109.5 degrees - in the case where the central atom is bonded to 4 identical atoms.
15
Q
What is the octet rule?
A
Each atom will fill its valence shell with 8 e-
16
Q
If mass of the box (m) is held constant, what is the result of doubling the value of the spring constant (k) on the distance an object moves?
A
The spring will only stretch half as much
17
Q
What is the torque equation?
A
t = F * d * sin(theta)
18
Q
What is the tension equation?
A
m1gsin(theta) = tension force
19
Q
How will a horizontal beam experience translation when it is released from a pivot point on one end?
A
A board will move around its hinge, and its center of mass will move down and to left as the board rotates around the pivot point. The center mass will be translated.
20
Q
How do you find the number of individual ions present in a 1 L solution of 1.5 M NaCl?
A
1.5 mol NaCl x (6.02x10^23 molecules)/1 mol NaCl x 2 ions / 1 molecule = 18.06x10^23
21
Q
What are the steps in calculating a percent yield?
A
- Balance the chemical equation; 2. Find limiting reagent; 2a. Based off of limiting reagent you are able to find theoretical yeild; 3. divide actual yeild by theoretical yield adn x 100%
22
Q
How many moles of H are there in 13.5 g of H2O?
A
13.5g H2O x (1 mol H2O / 18 g) x (2 mol H / 1 mol H2O) = 1.5 mol H
23
Q
What is a limiting reagent?
A
The limiting reagent is that which is used up first in a chemical reaction. Theoretical yield is defined as the amount of product expected to form from the complete reaction of the limiting reagent, assuming that the reaction goes perfectly.
24
Q
What are the untis for energy?
A
(Kgm)/s^2 - (Kgm^2)/s^2 - N*m - J
25
What is the equation for kinetic energy?
KE = (1/2) * m * v^2
26
What is equation used to compare the amount of work output when only given velocity (i.e. KE)?
W = KE final - KE initial
27
Which way will the reaction lean towards during equilibrium?
The forward and reverse reaction rates are equal
28
What equation is used to find partial pressures when given a partial pressure and Kp (an equilibrium constant?
Kp = P / P^2
29
Is a reaction that has negative change in G and a Keq that is > 1 spontaneous or non-spontaneous?
Spontaneous
30
How will the velocity of a skater at the center of the ramp with sloped edges compare to the velocity of the skater at the center of a ramp with incline plane edges?
The velocities will be the same, because when comparing the PE of both ramps they are equal (PE = mgh)
31
What three forces are act on a skateboard as it rolls along at a constant speed on a frictionless surface?
1. Weight of skater on board 2. Gravity of board down on earth 3. Normal force pushing up on the board
32
What equation could you use for a collision equation when looking to find the final distance traveled?
KEi + PEi = KEf + PEf
33
What is the identity of the precipitate formed by combining the iron (III) nitrate, Fe (NO3)2, and sodium sulfide, Na2 S, solutions?
Fe2 S3
34
Which of the following elements are transition metals and found in period 5? (Mn, Cd, Si, OS)
Cd
35
What is 0 K in Celsius?
-273.15 C
36
What does Le Chateliers principle state?
If disturbed, an equilibrium mixture will shift to relieve stress from a reaction. (i.e. If heat is a reactant and there is an increase in heat on the reaction, there will be shift to the right or products will be favored.)
37
What is the product of the following reaction: sulfer dioxide (SO2) and water (H2O) -> ____ ?
SO2 + H2O -> H2SO3 (Sulfurous acid)
38
Is enthalpy (H) + or - for an endothermic reaction?
enthalpy is + H
39
What are the characteristics of an ideal gas?
Real gases composed of small molecules that do not experience significant intermolecular interactions
40
What equation would you use to identify the rate of effusion of two different molecules mixed up in the same container?
Since the two gases are mixed together in the same container at the same temperature, the rates of effusion depend only on the molar mass of each molecule. This relationship is described by Graham’s law.
41
What are the changes to bloiling point at higher altitudes compared to sea level?
Atmospheric pressure at high altitude is lower than at sea level, the difference between the vapor pressure of water and the atmospheric pressure is smaller and the liquid boils at a lower temperature.
42
What is constant during phase transitions?
Temperature is constant during phase transitions, but the total energy continues to increase as heat enters the system. Since temperature directly reflects the average kinetic energy of the molecules in a system, the average kinetic energy is also constant during the transition.
43
What is the equation of absolute pressure?
P abs = P atm + p*g*h
44
In a convex meniscus what forces are dominating?
Convex = cohesive forces of surface tension > adhesive forces of container
45
What equation should be used to solve this equation? A large bucket is filled to the brim with water and a small hole is drilled in the wall of the bucket. If the bucket is 50 centimeters deep and water escapes from the hole at a speed of 2 m/s, where is the hole located?
Bernoulli's equation: P1 + 1/2 * p * v1^2 + p * g * h1 = P2 + 1/2 * p * v2^2 + p * g * h2
46
An object has a specific gravity of 0.60. What percent of the object’s volume will be found above water when it is placed in a liquid with a specific gravity of 2.0?
0.6 / 2.0 * 100 = 30% submerged. Now subtract from 100 to find the % out of water, which is 70%
47
What is a nonzero dipole moment?
To have a dipole, there must be polar covalent bonds and an asymmetric molecular structure.
48
How is temperature related to KE?
Temperature is directly related to KE. (i.e. KE = 3/2*k*T)
49
What is the formula for nitrous oxide?
N2O
50
What is the continuity equation?
V1 * A1 = V2 * A2
51
What is equation for Poiseuille's law and what is the result of doubling the length of a tube?
EQ: P = 8 (viscosity)*L*Q / (3.14 * r^4) If L is doubled then the pressure will be divided by two.
52
What is a valid way of representing pressure in units?
J/m2 and N/m3
53
When the ambient temperature is above 37 °C, by what method can the body most effectively cool itself?
When the ambient temperature is above physiological temperature, then passive processes (i.e. radiation, conduction and convection) will all transfer heat into the body. In order to cool the body there must be a net outward heat transfer, evaporation of sweat from the skin.
54
What shape is the graph of a second order reaction that has 1/[A] vs time?
Linear
55
A reaction is second order overall: first order for reactant X and second order for reactant Y. If the initial concentration of Y is tripled while the initial concentration of X is decreased to one-third its original value, how will the initial rate be affected?
Three times the original rate
56
3 NO + O2 → 2 NOCl
| If the concentration of NO is doubled, how will the measured initial rate change?
It will be increased by a factor of 8
57
What happens to the electric field when two negative charges are brought together very closely (but not touching)?
As the negative charges move closer together the electric field becomes stronger, which causes the field lines to become closer together.
58
What is the result in work done by an electric field if a charge travels parallel to two other parallel charged surfaces?
The parallel surfaces containing oppositely charged particles do no work on the charge traveling along a parallel path parallel to the other two surfaces
59
How does resistance change with length and radius?
Resistance decreases with decreasing length and increasing radius
60
What are the units: joules (J) / Coulomb (C) used to denote?
Electrical potential
61
What equation is used to solve for electrical potential?
Electric potential = (k * Q1) / r
62
If a compound is a stronger acid than another compund, will the conjugate base of the stronger acid have a high pKb value?
Yes, the conjugate base to the strong acid will have a higher pKb value compared to the other conjugate base.
63
How can you calculate the normality of a solution? (Ex: normality of 0.75 M of H2SO4 ?)
Simply multiply the molarity of the acid solution by the number of acidic protons per molecule. (0.75 x 2 = 1.5 normality)
64
What will happen to the Kw and pKw as the temperature increases?
As temperature increases the the Kw also increases and the pKw decreases. This means that both pH and pOH must be less than 14
65
What is the pKb of an ion that has a Ka of 7.0 x 10^-4?
0.7 - 4 = 3.2 (Kb) - 14 = 10.7 (pKb)
66
What is the pH of a 10.0 M HI solution?
To calculate: -log(10.0) = -1
67
How many ml's of a 1.0 M acid must be added to reach the equivalence point of 50 mL of a 2.0 base in solution?
100 mLs of an acid
68
What is the rate law equation?
Rate = k [A]^x [B]^y
69
What is a radical species and what molecule will likely not exist in this state?
A radical is a species with one or more unpaired electrons. N2 has a triple between the atoms and has no unpaired electrons.
70
What is the entropy change for rxn 1? N2 (g) + O2 (g) -> 2 NO(g)
Simply look to phase changes and count up the number of moles of gas present in both the reactants and the products. More moles of gas means more entropy. Here, there are two moles of gas in both the reactants and the products, so the entropy change will be zero.
71
For a zero order reaction, what is the rate law equal to?
The rate law is equal to the rate constant
72
What is the shape of the line on a graph for a second order reaction?
For a 2nd order reaction the plot of 1/[A] vs time is a straight line and K=slope of line. ------ [A] vs time or ln[A] vs time will be curved for a 2nd order.
73
What is an alpha carbon?
An alpha carbon, or the carbon adjacent to a C=O functional group. It is typically more acidic than other groups of C-H bonds
74
Is LiAlH4 a reducing or oxidizing agent?
LiAlH4 a reducing agent
75
What functional group is present is all triglyceride molecules? (Amide, Ether, Ester, or Aldehyde)
An ester
76
What nitrogen-containing functional group is charachterized by having a carbon-nitrogen double bond? (Imine, Enamine, Amine, Amide)
An imine has a carbon-nitrogen double bond
77
Reducing agents (electron donors) such as NaBH4 will more readily react with ketones and aldehydes, while displaying less reactivity towards esters and carboxylic acids, why?
Reducing agents (electron donors) such as NaBH4 will more readily react with electrophilic sites on ketones or aldehydes vs lesser eletrophilic sites like esters or carboxylic acids.
78
Assume that Team 1 pulls with a force of 100 N and Team 2 pulls with a force of 100 N. What is the tension in the rope?
In this scenario a force balalnce exists. If each team continues to apply a balanced force to each side, no individual team will budge forward and the rope will experience the value of tension being applied by only ONE team = 100 N
79
What does Newton's third law state?
Newton’s third law states that for every action there is an equal and opposite reaction.
80
What is the equation for work?
W = F * d * cos(theta)
81
If question is asking: "What molecule has the lowest pKb value?"
Essentially the question is asking you to identify the strongest base.
82
What is the scientific notation for pico?
Pico = 1 x 10 ^ -12
83
What are some examples for units of current?
Current = movement of charge. Ex: C/s, V/Ohms, W/V
84
True or false: A material obeys Ohm's law if its resistance does not change with increasing current.
True. Ohm's law states: V = I*R. If current is increased then voltage will increase adn resistance remains unchanged.
85
What is the equation to solve for power dissipated by a resistor?
P = IV = I^2 * R = V^2 / R
86
What is the equation to solve for work in a circuit?
W = 1/2 * C * V^2
87
What is the oxidation state for Cl in the molecule HClO2 ?
Hydrogen has an oxidation state of + 1, except in metal hydrides; this is not a metal hydride. When not in a peroxide, oxygen has an oxidation state of –2. This gives us a total of (+1) + 2(–2) = –3. Since the overall HClO2 molecule is uncharged, the oxidation state of Cl must be +3.
88
What is an oxidizing agent?
It is a molecule, ion, or element that oxideizes another species by becoming reduced itself.
89
A glavanic (voltaic) cell is __________ (spontaneous/non-spont) and thus must have a ____________ (positive/negative) overall E cell. If given the following two half reactions: Ag (s) → Ag+ (aq) + e− = −0.80 V
Au (s) → Au2+ (aq) + 2 e- = −1.50 V Which must occur at the anode?
Spontaneous, Positive, Silver (Ag) must be oxidized and gold must be reduced if we want our overall standard cell potential to be positive
90
In a galvanic cell, what is the function of the salt bridge?
It allows positive ions to move towards the cathode and negative ions to move toward the anode.
91
What type of reaction (oxidation/reduction) occurs in an alkene -> alkane transformation?
This is a reduction. Gain of an e-. Decreased oxidation state. Formation of a C-H bond (e.g. alkene -> alkane)
92
Pairs of compounds that differ in the orientation of at least one, but not all, chiral centers. The above describes what type of isomer?
These are characteristics of diastereomers
93
If a molecule has a stereocenter with priorities that indicate a counterclockwise direction, what will the configuration be (R/S)? (Note: the lowest priority points into the page, which is the default method)
S = counterclockwise (in default) R = clockwise (in default) **If lowest priority points inward (dashes) toward page, then configuration is flipped.
94
A carbonyl group (C=O) is reduced to a hydroxyl (C-OH), which decreases the oxidation state of the carbon. What rxn would be paired to make this occur? A. FAD → FADH2
B. NADH → NAD+
C. hexanoic acid → hexanal
B. is an example of an oxidation reaction, because NADH is the reduced form of this biomolecule and NAD+ is the oxidized form.
95
What is the difference between an enamine and an imine?
Imine = Carbon double bonded to a nitrogen (C=N) Enamine = Involves a C=C-NR or a C=C adjacent to a C-N bond.
96
How do you calculate the combination of capacitors in series and in parallel?
Capacitors in parallel: C eq = C1 + C2 ... Capacitors in series: C eq = 1/C1 + 1/C2 ...
97
What is the efect of introducing a dielectric into a capacitor?
Introducing a dielectric decreases the total electric field strength between the plates, decreasing the voltage, and increasing the capacitance. A capacitor with a dielectric in it is more effective and removing the dielectric will increase the total electric field strength between the plates, which increases the voltage, which decreases the capacitance.
98
What type of reaction is depicted by a leaving group being ejected from the opposite side of the molecule by an incoming nucleophile in the transition state? (Note: this reaction produces an inversion of stereochemistry.)
This is consistent with an SN2 reaction.
99
Esterification of the C-terminus of the tripeptide AFS could be accomplished with which of the following reagents? A. Concentrated aqueous sodium hydroxide
B. Acetic anhydride with catalytic pyridine (a non-nucleophilic base)
C. Excess ethanol with catalytic sulfuric acid
D. Hydrogen gas with a platinum catalyst
Excess ethanol with catalytic sulfuric acid
100
What substitution reaction and conditions are favorable to produce a racemic mixture of products?
An SN1 reaction with tertiary substituents are favorable. In other words, a LG located at the most substituted position, because SN1 rxns have a carbocation intermediate, which needs to be very stable.
101
What is the difference between resonance and tautomerization?
Tautomerization is moving around bonds while resonance is only moving around electrons.
102
What is the relationship between length and frequency?
It is linked by the pendulum equation: T = 2 (Pi) (L/g)^1/2 This answer gives the period, so to get the frequency, you must find the reciprocal of T.
103
What happens to the frequency of a sound wave as it enters a new medieum?
It remains the same. NO CHANGE!
104
What units can accuarately represent the intensity of a sound wave?
Decibels, W/m2, kg∙s^3
105
What is the criteria that liquid-liquid extraction separates acording to?
Liquid-liquid extraction separates according to a compound's solubility
106
Wha compounds are most easily identifiable using UV-Vis spectroscopy?
During UV-Vis spectroscopy, conjugated compounds demonstrate high levels of absorbance.
107
In a normal-phase HPLC, what is the first compound to elute from the column? (polar vs nonpolar)
Normal-phase HPLC features a nonpolar solvent that is run through a column packed with a polar solid. Since polar solutes are attracted to the polar solid in the column, they pass more slowly through the column and elute after nonpolar solutes.
108
What can be known about change in G, if E cell > 0?
If E cell > 0 V, this indicates that the cell will be spontaneous and means that change in G is > 0.
109
In an electrolytic cell, if Ni(s) has a greater reduction potential than Cd(s), which species will be located oxidized at anode and which will be reduced at cathode?
As it is a electrolytic cell, the Ni will be oxidized at the anode and the Cd will be reduced at the cathode.
110
What is the equation for Hooke's law for springs?
F = -kx. The degree to which a spring deforms (x) under a force (F) is proportional to k (Hooke's constant).
111
What aspect of sound is affected as it travels through a medium?
The speed of sound through a medium is primarily determined by the bulk modulus of that material (slightly affected by density as well). Stiffer materials have a higher bilk modulus and so sound moves more quickly through stiffer material.
112
What is the numeric value for the metric unit of M (Mega)?
M = 10^6
113
What property of a wave casuses a direct impact on displacement? (Velocity, Amplitude, Frequency, Wavelength)
Waves with higher amplitudes are capable of causing greater displacement.
114
Anion-exchange chromatography uses _______ (positively/negatively) charged molecules within the column to trap _______ (positively/negatively) molecules within the column. This allows______ (positively/negatively) charged molecules to elute first.
1. Positively (in column) 2. Negatively (trap) 3. Positively (elute first)
115
What is percent of incident light passes through two perpindicular linear polarizers (light filters)?
In general, almost all light is filtered out, with none being passed through the second filter.
116
When does total internal reflection occur?
Total internal reflection occurs only when traveling from a material with a higher refractive index to a material with a lower one.
117
What shape is a mirror with a focal length of -2 m?
It must be a convex mirror. Convex mirrors always form virtual images.
118
What is the thin-lens equation?
1/f = 1/o + 1/i
119
How can you find the power of a lens given only the radius of the lense?
Focal length is half of the radius. Power is the reciprocal of focal length.
120
What type of lense may be used to correct myopia (nearsightnedness)?
This condition can be corrected using a diverging lens which will increase the image distance and allow the image to focus later.
121
What is net the result of a single round of alpha decay?
The net result of a single round of alpha decay is the loss of two protons and two neutrons from the parent nucleus. Since four nucleons are lost, the mass number decreases by 4.
122
What force is primarily responsible for holding together the nucleus?
The strong nuclear force is the main attractive force within the nucleus.
123
True or false: On an absorbance spectrum for a molecule obtained using spectrophotometry, the color of that molecule can be determined by examining regions of high absorbance
False. The color of a molecule can be determined by examining regions of low absorbance.
124
How is the radius of Poiseulle's law related to the actual flow rate?
Flow rate (Q) = r^4
125
Assuming the volume remains constant, how would the pressure of a gas inside a canister change if the temperature of that gas was doubled?
The partial pressure of that gas would double. It obeys the ideal gas law: PV = nRT
126
What aspect of the root-mean-square speed equation changes based on the molecule?
The molar mass (M) changes. The root-mean-square speed of a gas increases as the molar mass decreases. Vrms = (3RT/M)^1/2
127
What equation could you use when given a problem that involves something that stretches (like a spring)?
Use the Hooke's law: F = -k*x
128
What is charge and potential at the anode and cathode in a SDS-PAGE?
SDS-PAGE electrophoresis requires an external power source (like an electrolytic cell). This means the anode will be positive (higher potential), and the cathode will be negative (lower potential).
129
What happens to the bright spots on the screen if the distance between the laser pointer and the diffraction grating is increased? (Changes in distance between spots or size/brightness of spots/)
Distance and brightness/size of spots remains the same.
130
If a laser was fired in vacuo, what is the velocity of the beam if it reflects off of a diffraction grating and has a frequency of 100 MHz?
In vacuo means in the vacuum of space. All light travels with the velocity of c, 3.0 ⨉ 108 m/s when in space. Do not be distracted by all the extraneous information.
131
What is the result of a beta (-) decay? ....what is the result of a beta (+) decay?
Beta (-) decay = a neutron is converted into a proton in the nucleus and an e- is ejected. Beta (+) decay = a proton is converted into a neutron and a positron is emitted.
132
What is a teratogen?
A teratogen is any substance that causes a malformation of an embryo
133
How does mass spectrometer work?
Sample particles are ionized, accelerated by a potential difference (voltage), passed through a velocity selector such that all the particles that enter the uniform magnetic field will share the same velocity. Once inside the magnetic field these charged, moving particles will experience Lorentz forces and begin to move in a circle, with the particles path radii determined by their mass to charge ratio.
134
What does an ammeter measure?
An ammeter measures current. An ammeter could also be used to measure the strength of an action potential, as neurons are very similar to a current carrying wire.
135
Where is the pKa on a titration curve?
The pKa occurs at the half-equivalence point. When pH = pKa the [A-] = [HA]. On a titration curve, this is approximately at the midpoint of the initial horizontal part of teh curve.
136
What makes an indicator accurate for a titrant?
An accurate indicator for a titration will have a pH range of color change that includes the equivalence point of the titration, ±1. The equivalence point of a strong acid/weak base titration will be less than pH 7
137
What monochromatic color has the lowest velocity when passing through a prism? Given: Red light is refracted least and blue light is refracted the most.
As blue light is refracted the most it will be the slowest. Ref. equation n = c/v
138
What aspect of light is impacted when it enters a medium with n > 1?
The velocity will decrease below 3x10^8 m/s
139
What is the approximate molarity of sodium chloride in ocean water, if the density of ocean water is 1.028 kg/L? (Given: 3.5% is NaCl by mass, molar mass of NaCl = 58 g/mol)
1. (1028 g)(0.035) = 36 g NaCl 2. (36 g NaCl) / (58 g NaCl / mol) = 0.62 moles 3. 0.62 moles / 1 L = 0.62 M
140
What would happen to water in cells of the body if a person drank hypersaline ocean water?
The blood would become hypertonic, and water would rush out of the cells via osmosis
141
What is the effect of adding salt to water in terms of boiling point?
Adding salt reduces vapor pressure of the liquid. A reduction in vapor pressure means increase in BP. As solute concentration increases, the rate water mols break the liquid surface decreases.
142
What are the characteristics of water that make it float?
Solid water (ice) is significantly less dense than the liquid form. The water mol being bent at angle of 104.45, plus a high degree of hydrogen bonding between water mols leaves a structure with TONS of empty space.
143
What does Beta-minus decay?
Beta-minus decay: A neutron is converted into a proton in the nucleus and an electron is ejected to maintian charge balance.
144
What purpose do boiling chips and vacuums serve in the process of distillation?
1. Boiling chips provide nucleation sties. When liquids transition from liquids to solids they require nucleation sites, or places to start forming bubbles. 2. Vacuums are used to reduce the atmospheric pressure, thereby lowering the temperature at which a liquid needs to reach IOT begin to boil.
145
If two fluids reside in a flask, how can you know which one will be left after a distillation?
The liquid with the lower BP will boil off first, leaving the remaining liquid in the flask - left over.
146
How would you go about solving: A mass of 10 kg is dropped from a height of 20 m. Ignoring air resistance, what is the maximum speed achieved by the mass? (assume g = 10 m/s2)
Use KE = PE PE = mgh (10 kg x 10m/s^2 x 20 m) = 2000 J 2000 J = 1/2 x m v^2 (1/2 x 10 kg x v^2) Solve for v v = 20 m/s
147
What period of elements have the most stable octet?
Noble gases have a complete octet and therefore are the most stable.
148
What is the equation for torque?
T = r x F x sin (theta)
149
A book experiences a gravitational force due to the earth's gravity, according to Newton's Third Law, what is the effect of this book resting on a table?
The earth experiences a gravitational forms of mg from the book.
150
Acetone has a central carbon atom that is double bonded to an oxygen and single bonded to two other carbon atoms, w/o any lone pairs. What are the bond angles for acetone?
120 degrees
151
How does one add up resistors in parallel vs in series?
Parallel = 1/R1 + 1/R2 + 1/R3 Series = R1 + R2 + R3
152
Which of the following biological substances are likely derived from terpenes?
I. Aldosterone
II. Glucose
III. Insulin
IV. Estrogen
Terpenes are structurally similar to the fused 4-ring system in steroids and are the precursor molecule. Most steroid hormones end in "-one", "-en", "-or", "-ol"
153
What is the function of a transferase enzyme?
Transferases move functional groups from one molecule to another.
154
True or false, the angle of incidence always equals the angle of reflection?
True
155
True or false: the rate of cation formation via loss of a hydrogen atom is directly related to the energy related to remove a hydrogen atom.
True, the more energy required, the slower the rate.
156
As the relative stabilization energy (RSE) becomes more negative, what is the result on the overall stabilization?
The more negative the RSE, the more greater the stabilization.
157
In order for a reaction to produce heat or to be exothermic the enthalpy must be ______.
All exothermic reactions have a negative enthalpy in the overall reaction -> H reaction = H f products - H f reactants
158
At what temperature (high/low) will a reaction that has a (-) enthalpy and a (-) entropy be spontaneous?
It will be spontaneous only at low T
159
The following describes what electrical device? Charges will accumulate on plates when voltage is applied.
This describes parallel-plate capacitors
160
What is the cause of the phenomenon of "dry heat" feeling subjectively cooler a result of?
The lower the humidity allows water to evaporate more easily, increasing sweating. That increased sweating helps keep the body cool.
161
What aspect of light does not change when it moves between media of different refractive indicies?
Frequency always remains constant.
162
What is the equation for wavelenght in open pipes?
Lamda = 2*L/n (n = # of relevant harmonic, 2nd harmonic means n = 2)
163
What is the velocity of a mass on a spring that is at the extreme of its oscillation?
A mass will be at zero velocity at the extreme of its oscillation.
164
What does it mean if a boat has a specific gravity of 491 kg/m^3 (pure water has a density of 1000 kg/m^3)?
This tells us that 49.1% of the object will fall beneath the surface.
165
What is the density of water?
Water has a density of approximately: 1 g/cm^3, 1 g/ ml, 1 kg/L, 1000 g/L
166
What type of meniscus is present if adhesive forces are greater between fluid and glass?
A concave meniscus would be formed due to fluid being more attracted to the glass than other particles (adhesive forces)
167
What equation can you use to find the flow rate or cross-sectional area of a flowing liquid?
The continuity equation, A1*V1 = A2*V2
168
What is Coulomb's law in an equation format?
F = k * (Q*q/r^2)
169
For resistiors in series, do you add them up as whole numbers or as inverse numbers?
Resistors in series are added together as whole numbers.
170
What is the impact on capacitance if the radius is increased by the square root of 2?
This would double the area = doubling the capacitance
171
Will adding a second parallet resistor that is twice the length of an existing resistor change the resistance of the system?
No, this additional resistor provides an alternate pathway for charge to move through.
172
In order for the Gibbs Free Energy equation to be spontaneous (-G), what must be true for this interaction when T is positive? I. H > G II. 0 < S III. H < S
I. H (enthalpy) > G (Gibbs energy) II. 0 < S (entropy)
173
What type of orbital would require a short electromagnetic radiation wavelength to eject an electron from within?
A very short EMR wavelength would be required to eject an electron an sp orbital (e.g. gamma rays). Whereas a longer wavelength could be used to eject an electron from a sp3 orbital.
174
Which of the following particles have the least mass? A. Alpha particle B. Beta particle C. Positron D. Gamma particle
A gamma particle is a photon of electromagnetic energy, which does not have a mass.
175
Where on the periodic tables are the elements wth the largest atomic radii?
Elements with the largest radii are found nearest the bottom left of the periodic table.
176
What would be a way to increase the completeness of a fraction?
Increasing the length of a column will enhance the resolution of the column and leads to a more complete fraction by SEC.
177
What does Charles' law state about the relationship between the volume of an ideal gas and its temperature (when pressure is constant)?
It states that there is a direct relationship between the volume of ideal gas and its temperature. (V1)/(T1) = (V2)/T2)
178
What is the relationship between two isomers that are non-superimposable mirror images (like your hands)?
These are called enantiomers
179
What vitamin functions as antioxidants?
Vitamin E refers to a set of closely-related, lipid-soluble compounds that function as antioxidants.
180
True or false, the doppler effect may analyze moving or stationary objects and fluids.
False, the doppler effect is used to analyze moving objects and fluids. A doppler shift will only be registeered if the fluid is moving relative to the source of the sound.
181
What does the azimuthal quantum number indicate?
The azimuthal quantum number for an atomic orbital determines its orbital angular momentum and describes orbital shape.
182
What has to be true of the critical angle in order for a light ray to be totally internally reflected?
The light ray must hit the edge of the glass at an angle equal to or greater than the critical angle.
183
If an IR absorption spectrum were obtained for a compound, which showed a strong signal at 1100 cm-1, what would this most likely indicate the presence of?
A C-O bond stretching typically exhibits a frequency range of 1000-1320 cm-1.
184
If an IR absorption spectrum were obtained for a compound, which showed a strong signal at 2200 cm-1, what would this most likely indicate the presence of?
A CC (triple bond) stretching typically exhibits a frequency range of 2100-2260 cm-1.
185
What is the result of the deshielding effect on protons in an NMR spectrum?
The deshielding effect will lead to increased chemical downfield shifts due to removal of electron density.
186
What is the transition from a vapor pahse directly to a solid form known as?
Deposition refers to a gas-to-solid transition.
187
What are beta particles?
Beta particles are either electrons (beta - particels) which have a -1 charge, or positrons (beta+ particles), which have +1 charge.
188
What are alpha particles?
Alpha particles (helium nuclei) have a +2 charge.
189
In column chromatography at physiological pH, using a stationary medium with a net positive charge, what types of molecules will elute first?
If the stationary phase has a net positive charge, then the more negatively charged molecules will be attracted to the stationary phase and elute more slowly compared to the more positively charged molecules, that will elute faster.
190
What is true about the pKa value of a very weak acid?
A very weak acid will have a very large pKa value. (pKa + pKb = 14)
191
What type of solvents would lead to the fastest SN1 rxn?
SN1 rxns occur faster in protic solvents. Ex: propanol
192
What is the function of pepsin?
Pepsin is an enzyme released in the stomach that catabolizes proteins into smaller peptides and AAs.
193
What is a furan?
A furan is a heterocyclic, five-membered aromatic ring with four carbon atoms and one oxygen.
194
What charachterisitcs facilitate a compound to be fast and the first peak in gas chromatograph (gc) trace?
The compound will exhibit low molecular weight and weak intermolecular forces.
195
What is the comparison of electrons to an ion?
Ions are thousands of times more massive than the e-. The hydrogen ion is the lightest ion and is nearly 2000 times larger than the e-.
196
What is the equation for wavelength?
Wavelength = speed / frequency
197
What is the percieved frequency when a sound source moves away from an observer?
A sound source moving away from an observer appears to have its source frequency shifted to a lower frequency.
198
How would a negatively charged particle react to being placed near a fixed positively charged particle (Q)?
The Coulomb force between the negative and positive charges is attractive. The force accelerates the neg charged particletoward the pos charged particel.
199
How do charges travel through electric field lines between inside of an axon and the surrounding extracellular solution?
The electric field lines exit from positive and enter negative charges. The axon is neg charged and the extracellular solution has a zero net total.
200
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If channel X transmits only the smallest substances dissolved in the extracellular fluid through the axon membrane. Which substance would Channel X transmit?
A.Proteins
B.Sodium ions
C.Potassium ions
D.Chloride ions
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Channel X would transmit sodium ions, as these are the smallest listed.
201
How would you find the closest distance to place an electrode to measure voltage change if given time and rate of speed?
Multiply time (sec) x speed (m/s) = m
202
What variables are needed in order to calculate the current of a pulse?
Ohms law: I = V/R, require: resistance per unit length, the length, and potential V
203
Compounds with the general formula: AOm(OH)m are _____ if A is a non-metal.
acids
204
The structure of squalene, a triterpene, is highly suggestive of its transformation to a fused four-ring system, what type of molecule will this likely be?
The fused four-ring system is common to cholesterol and all of the steroid hormones.
205
What is the concentration of Cl- ions in a 0.1 M solution of calcium chloride?
0.20 M, as the formula is CaCl2, so the amount of Cl- is multiplied by 2.
206
In reverse phase high performance liquid chromatography (RP-HPLC), what type of compound will elute first (polar vs non-polar)?
In RP-HPLC, the more polar compound will elute first.
207
What is the y-intercept on a Lineweaver-Burk plot equivalent to on a Michaelis-Menten model?
The y-intercept on Lineweaver-Burk = 1/Vmax on Michaelis Menten
208
NADPH + H+ + O2 + R–H → NADP+ + H2O + R–OH
In this reaction, NADPH functions as:
NADPH is acting as a hydride transfer agent, which reduces oxygent. (Reducing Agent)
209
What type of reaction is this: 2HCl(aq) + Mg(s) → MgCl2(aq) + H2(g)
This is an Oxidation/reduction because atoms involved change oxidation states during the reaction.
210
The principal quantum number is a measure of which of the following?
The principal quantum number n is most closely associated with the potential energy of the electron. It is also the approximate radial size of an electron cloud.
211
What is occuring in the following rxn NADH -> NAD+ ?
NADH is being oxidized to NAD+
212
What is the name given to a negative Beta particle during the nuclear decay of a heavy nucleus?
A negative beta particle = an electron
213
What is the name given to a positive Beta particle during the nuclear decay of a heavy nucleus?
A positive beta particle = a positron
214
When forming a polypeptide, what two atoms are the site of covalent attachment?
Peptide bonds are formed when the amine group of one amino acid binds with the carbonyl carbon of another amino acid.
215
What is the equation used to solve for light energy?
E = h *f or E = h * c / lamda
216
What is a picometer (pm)?
Pico = 1 x 10 ^ -12
217
What is a nanometer (nm)?
Nano = 1 x 10 ^ -9
218
What is a micrometer (μm)?
Micro = 1 x 10 ^ -6
219
What is a megameter (Mm)?
Mega = 1 x 10 ^ 6
220
What is the result of UV light absorption by organic molecules?
The absorption of UV light by organic molecules always results in the electronic excitation or bound e-
221
When using silica gel as the stationary phase for column chromatography, what type of molecule will elute the fastest?
As silica gel serves as the stationary phase, mols with increased polarity will have increased affinity for the stationary phase and increase elution time (decreased Rf)
222
The half-life of a radioactive material is:
The half-life of a radioactive material is the time it takes for half of the radioactive nuclei to decay into their daughter nuclei, which may or may not also be radioactive.
223
Why must the person either lean forward or slide their feet under the chair in order to stand up? A.To increase the force required to stand up
B.To use the friction with the ground
C.To reduce the energy required to stand up
D.To keep the body in equilibrium while rising
D. The only support comes from the feet on the ground. The person is in equilibrium only when the center of mass is directly above their feet.
224
What would be a better subsitution for a phosphorylated threonine in an AA sequence, Glutamic acid (E) or Glutamine (Q)?
The phosphorylated threonine would be best mimicked by glutamic acid in terms of size and charge
225
What does a curve with a sigmoidal shape indicate about a reaction?
As the shape of the curve is sigmoidal, it indicates that this is a cooperative binding process.
226
What are the structural features possessed by storage lipids?
They consist of three fatty acids ester-linked to a single glycerol.
227
What is the function of a lewis base?
A lewis base is a substance that donates an e- pair in forming a covalent interaction.
228
What does it mean for the reaction if the equilibrium constant is >1 ?
If K > 1, then reaction will produce mostly products
229
What is the type of bond between Cu2+ and the nitrogen atoms of the ammonia molecules in [Cu(NH3)4]2+?
The lewis acid-base interaction between a metal cation and an e- pair donor is known as a coordinate covalent bond.
230
What is the equation for power consumed?
P = PE / t = mgh / t
231
What does a negative focal length indicate about a lense?
A negative focal length means that it will be a diverging lense. These form virtual and reduced images of objects at distances > the focal length.
232
Zn has an oxidation potential of +0.76, while Al has an oxidation potential of +1.66. Which metal serves as the better oxidizing agent?
Here, Zn has a less positive oxidation potential; and less likely to oxidize than Al. After switching the signs of the reactions to find their reduction potentials. Zn2+ has a reduction potential of -0.76 and Al has a reduction potential of -1.66. Zn2+ is the better choice for an oxidizing agent.
233
A higher reduction potential represents what compared to a lower reduction potential?
A molecule with higher reduction potential is likely to spontaneously reduce than the lower potential.
234
In electrolytic cells the ______ redox half-reaction will take place thanks to the external current.
In electrolytic cells the nonspontaneous redox half-rxn will occur. (In contrast, in a glavanic cell the spontaneous redox half-rxn will proceed)
235
Nickel-cadmium (NiCd) batteries are rechargeable cells used in remote-control toys and airplanes. An NiCd battery in the process of discharging is most analogous to what type of cell:
It is similar to the spontaneous process seen in galvanic cells.
236
What is the typical resting membrane potential in human neurons?
-70mV is typical resting potential
237
What is the [K+ outside] vs [K+ inside] of a human neuron?
[K+ inside] must be > [K+ outside]
238
What is the meaning of Kd in terms of binding substrates?
Kd is defined as Ne/(Na−Ne), where Ne is the number of occupied sites and Na is the number of available binding sites
239
What would be the approximate pH of a solution that had 0.5 moles of KOH and 1.0 moles of HCN (weak acid) in 1 L of water?
According to the Henderson-Hasselbalch equation, a solution that contains equal concentrations of weak acid and its own conjugate base constitutes a buffer with pH = pKa (acid) Solve: 0.62 - 10 = 9.38
240
What are the lenght of the sides of a special triangle that has a angles of 30, 60, 90 degrees?
Side adjacent to 60 degree angle = x, the hypotenuse = 2x, and the side adjacent to 30 degree angle = x*(3)^1/3
241
What is the e- configuration for Hg?
Hg configuration is: [Xe] 4f^14 5d^10 6s^2
242
What is the first step in a base-catalyzed aldol condensation?
1. Deprotonation to form an enolate. 2. Attack of that enolate to form a new carbon-carbon bond. 3. Reprotonation. 4. Reduction in the dehydration step. -OH is lost to form a beta-unsaturated ketone or aldehyde.
243
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244
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245
What are the most to least harmful types of decay?
Most harmful: Alpha particle Moderately damaging / mutagenic: Beta - and + decay Least harmful: Gamma decay
246
A jeweler wants to electroplate a coat copper jewelry with gold. If he operates an electrolytic cell at a 10 A current for 6 minutes, how many grams of gold will be plated? (Note: Faraday’s constant is 10^5 C/mol e–, and any gold cation is in the form of Au 3+
1. 10 C/s x 360 s = 3600 C 2. 3600 C x (1 mol e- / 10^5 C) = 3.6 x 10^-2 mol e- 3. (3.6 x 10^-2 mol e-) x (1 mol Au / 3 mol e-) = 1.2 x 10^-2 mol Au 4. (1.2 x 10^-2 mol Au) x molar mass of Au = (1.2 x 10^-2 mol e-) x (2 x 10^2 g Au / mol) = 2.4 g Au
247
What is the hourly energy loss due to perspiration? Given: perspiration rate - 4 L/hr, heat of vaporization of water - 600 cal/g, density of water - 1 g/ml.
Q = (4L / hr) x (600 cal / g) x (1 Cal / 1000 cal) x (1g / 1 ml) x (1000 ml / 1 L) = 2400 Cal
