Riyaz - CP - Flashcards
What is the emprical formula and the molecular formula of Glucose ?
1 mol contains avogrados # of particles(6.02x10^23). Multiply the moles by the Avogrado # of particles and the # of ions in the compound, whose #of ions present you are looking for
How do you calculate the percent composition of an atom x in the molecule xyz?
Emperical Formula - is the lowes-whole-number (simplest) ration of the atoms present in a molecule ex. acetylene molecular formula is C2H2, the emprical formula is CH.
Molecular Formula - Is the number of atoms present in a molecule
What are the different types of Reactions?
To calculate %composition of a atom in a molecule whose Grams of usage is not given calculate the formula weight. Then divide the mass of the of atom and divide it by the molar mass and multiply it by 100%
Calculate the actual or molecular formula of a compound whose empirical formula is given and has a mass of X amount of grams?
Decomposition Rxn: These are the opposite of synthesis reactions, with the format AB → A + B. Decomposition reactions “take things apart”. Just as synthesis reactions can only form one product, decomposition reactions can only start with one reactant.
Single displacement reaction: is a reaction in which 2 elements are substituted for another element in a compound. AB + C –> AC +B
Double Displacement: two compounds swap components, in the format AB + CD → AD + CB
Combustion: better known as burning, is the combination of a substance with oxygen. The products are carbon dioxide, water, and possible other waste products. C3H8 + 5O2 -> 3CO2 + 4H2O
How do you calculate the # of atoms x present in a molecule containg 40 grams xyz?
To find molecular formula from Empirical formula, First calculate the weight of the empirical formula to see if the molecular formula and empirical formula are the same. If not, Divide the actual weight from the empirical weight which gives the coefficient. Multiply the coefficient by the empirical formula and you will get the molecular formula
How do you calculate x in a sample weighing x grams. The average mass of that sample is y grams?
Calculate the # of moles of a molecule first then multiply it by the #of atoms in the molecule and then by the avogrado’s # to calculate the # of atoms of x present in the compound of a given weight
How do you convert micrograms to miligrams or grams and militers to liters
When asked to calculate the amount of something present in a sample of x , learn how to convert the units and solve for the answer.
How do you calculate for time when you want to raise the temperature of a substance by x amount of degrees?
Understand that 1 microgram equals 0.001miligrams and 1 ml equals 0.001Liters
Learn to convert properly to land the answer correctly
Learn how to convert to Meters, Kilograms and seconds sometimes Liters if asked for!
What is the Ideal gas law?
Need to know that temperature and seconds is directly proportional when asked how long it takes to raise the temperature of a substance to x degrees
What happens to the radius of a sphere if the volume decreases by x amounts? What happens to the diameter? What happens to the radius of the diameter increases by a factor of x amounts?
PV=NRT, know how to convert units
How do you rewrite a percent increase or decrease?
Understand that when the radius is increased by a factor, the diameter also increases by that same factor. For the volume of a sphere V=4/3(Pi)r^2. If the volume decreases by a certain factor then r decreases by square root that factor
Ex: volume decreases by factor of 27, then r^2 = 27, 3^3=27, means radius decreased by a factor of 3. This means the diameter changes or decreased by a factor of 3 aswell
How are length of a string and the period related for a pendulum?
understand a percent (x) if increased or decreased is the same as 1+(x/100) or 1-(x/100) respectively.
what is the equation for the pendalum?
Understand that in a pendalum, The period is directly related to the length of the string, If he length increase so does the period, but the length is a square root value. Therefore if the period increases by a factor, the lenght increases by a square factor of the period.
What is the Spring vibration equation as well as the relationship between the period of the spring and its frequency?
Understand the relationships between the variables of a pendulum equation.
How many protons are in the atomic element number 20?
Understand the spring equation and the relationships between the variabes as well as the relationship between the period and the frequency.
Frequency is inversely related to the Period–> F=1/T
What is the relationship between force and the radius of a charged particles near each other?
Understand that the mass number is the number of protons plus neutrons and the atomic number is the number of protons.
What is the relationship between two charged particles and force if the particles have the same charge?
Understand that the radius is inversely related to the force of a two charged particles. If r approaches zero then force is infinite but if r increases F approaches zero but never reaches it. Therefore the graph should have a negative parabolic motion.
How to calculate Km from a graph?
Understand that if both charged particles have the same charge it becomes Q^2 instead of q1 and q2 for the equation F=Kq1q2/r^2. Understand since the particle has the same charges, the equation becomes similar to a quadratic equation and will have a parabolic graph
What is the effect of pi bonds of aromatic rings of the same system on the wavelength of light absorption?
Km is 1/2 the substrate concentration of the vmax - for a given Substrate conc vs. velocity graph.
What does the following mutation mean? G185D
large systems of conjugated pi bonds in aromatic rings tend to increase the wavelength of the light absorption
What is the catalytic efficiency of an enzyme with a Kcat of 5x10^2and a Km of 0.5?
The changes of amino acid residues on the mcat bio and chem phys passages given in the passage data usually are noted by a one letter abbreviation number of amino acid and the changed amino acid. Ex. L286V
What is the catalytic efficiency of an enzyme?
catalytic effiency of an enzyme is its Kcat Divided By its Km
How do you find the stereoisomers of a compound with x amount of chiral centers?
Given the units of a calculation question, make sure the units cancel out properly and allign with the answer choices or the units of the given in a question stem
Would a product of a rxn precipitate or dissolve in a solution if it exceeds the solubility constant?
When asked about the stereoisomers of a compound calculate the number of chiral centers and use the 2^n rule
What is the trend of Atomic Radii size of the periodic table?
A product precipitates and creates solid like structures when it exceeds the solubility constant (Ksp) number. If it is lower than the solubility constant then it will dissolve into the solution
What information do you need to calculate the Current?
Atomic Radii decrease from left to right of the periodic table and increases from top to bottom. Also know that like charges repel therefore a + ion will be attracted to a (-) area when a channel opens up
How do you find the pH?
Current is calculated from the Potential, the resistence per length and the length. You can use the equation I=V/R. But to find R you need the Resistence per length and the length. Or R=rho (L/A)
what is the conc of Na+ in a 0.2 M solution of NaCl?
pH= -log(H+) and the pOH= -log(OH-) and to get pOH you do pOH=14-pH
How does a saccharide go through mutorotation?
The molar conc of a ion in a molecular solution is dependent on the mole ratio compared to the other ions in the molecules.
What is a oxidation/reduction reaction?
If a Saccharide does not contain a hemiacetal group it will not go through mutarotation. It must go through mutorotation to be oxidized. Saccharide go through mutorotation if they undergo ring opening. Ring opening occurs at the site of hemiacetal group and the intermediate is a aldehyde
What are the parameters of the Doppler for the light image emitted?
Oxidation/reduction reactions involve the changing of the oxidation state of a atom or the transfer of electrons of a atom by gaining or losing.
Ionization reaction - is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons to form ions
What type of amino acids does a hydrophobic pocket prefer?
The Doppler effect relates the 1)frequency of ultrasound wave as used by the moving detector to the 2)frequency of the wave when the source is stationary,3) the speed of the source and the 4) speed of the detector.
Read the passage carefully where it discusses polarity and hydrophobicity of a substrate or ligand.
Read the passage carefully where it discusses polarity and hydrophobicity of a substrate or ligand.
Resistence and temperature are linearly proportional therefore they have a linear graph not a logarithmic - infer from the data.
Resistence and temperature are linearly proportional therefore they have a linear graph not a logarithmic - infer from the data.
When two reactants are reactant and neither are chiral - can a chiral center form?
When Asked questions in relations to the data read the date carefully of the reactions to understand what changes are occuring where and why.
What does Sublimation do?
When a two reactants are not chiral - they most likely will not form a chiral center unless the enzyme or solution consists of a chiral center
Sublimation keeps the water under reduced pressure and keeping the mixture cold.
Sublimation keeps the water under reduced pressure and keeping the mixture cold.
Hemiacetal and cyanohydrin will hydrolyze in acid and glucose molecules are usually connected with one another.
Hemiacetal and cyanohydrin will hydrolyze in acid and glucose molecules are usually connected with one another.
Read the question stem carefully and rationalize time properly - do not spend too much time on a question. If you do mark it and move on.
Read the question stem carefully and rationalize time properly - do not spend too much time on a question. If you do mark it and move on.
Rationalize time properly on mcat questions averaging 8-10 minutes per passage and do not spend too much time on one question. Mark and move on and come back to if time permits
Rationalize time properly on mcat questions averaging 8-10 minutes per passage and do not spend too much time on one question. Mark and move on and come back to if time permits
How do you increase the amount of product produced in a rxn?
Rationalize time properly on mcat questions averaging 8-10 minutes per passage and do not spend too much time on one question. Mark and move on and come back to if time permits
What is the Henderson Hasselback equation?
To get a increase of the product you must add more reactants, increasing the catalyst enzyme will only increase the rate the product is performed not increase the amount of product.
What is Avagrado’s number?
When asked to determine ratios of a solution for example acid to conj base, and given the ph and pka of a solution, you can use the henderson hasselbach equation to solve for the answer.
pH=pKa + logKa
pKa=-logKa
how to write standard atomic notation?
Avagrado’s number is 1mol= 6.02x10^23 and is used to get the mole equivalent when given the # of molecules. !
How to find electronegativity trend on periodic table?
In standard Atomic Notation -, the mass number (or the total number of neucleons - neutrons plus protons) is written above the atomic number, (the total number of protons)
what determines reactivity with water?
Electronegativity increases from bottom to top and left to right of the periodic table. The higher the electronegativity and closely related to atoms are the less ionic character they will have.
What is the difference between, Pauli Exclusion rule, Aufbau principle and the hunds rule?
Reactivity with water is heavily based on Ionization energy. Elements with low ionization energy tend to lose their electrons easily, allowing to rapidly for oxides with water. Group 1 ions are more reactive than group 2. Ionization energy increase bottom to top and left to right on periodic table
What is the Bohr Model?
Pauli Exclusion rule- states that no 2 electrons can have the same set of quantum numbers. Having the same spin in the same orbital will make it have the same quantum number therefore that is not possible under this rule.
Aufbau Principle - States that electrons fill orbitals in increasing order.
Hunds Rule - Each orbital must contain one electron before any electrons are paired.
Bohr Model of Atom - electrons orbit the nucleus at different distances. Additionally it states these distances must be related to the energy level of the associated orbital. If this is true, electrons must emit electromagnetic radiation at specific frequencies depending on the gaps between these levels. Energy emission should be quantized - wavelength of the emitted radiation was proportional to the energy difference and Plancks constant.
Bohr Model of Atom - electrons orbit the nucleus at different distances. Additionally it states these distances must be related to the energy level of the associated orbital. If this is true, electrons must emit electromagnetic radiation at specific frequencies depending on the gaps between these levels. Energy emission should be quantized - wavelength of the emitted radiation was proportional to the energy difference and Plancks constant.
What is the Azimuthal quantum #?
Principal quantum #?
Magnetic quantum #?
Principle quantum number changes from block to block, 3rd d- block has a p.q.n of 3, azimuthal quantum numbers of 2 and a magnetic quantum number ranging from -2 to 2 and a spin of -1/2 to 1/2.
What can the inital quantum number be for uv light?
Azimuthal Quantum # - the value that denotes the subshell and the angular momentum of an electron. Tells us whether a electron is found in the s, p, d, or f subshell and also used to describe the shape of the orbital.
Principal quantum # - corresponds to an electrons subshell and energy level. Found looking at elements row in periodic table
Magnetic Quantum # - Narrows down electrons location to a particular orbital within a subshell
how do you calculate effective nuclear charge?
All shells can exist in a initial excited state of n=6 in principal quantum # of uv, infared and visible light