MCAT Chem/Phys Flashcards
What is the difference between a vector and a scalar? Give examples of each
Vectors have magnitude and direction (Displacement, velocity acceleration), while scalars only have magnitude (Distance)
What is the equation for vertical and horizontal velocity
Vertical velocity = Vo(sin O), Horizontal velocity = Vo(Cos O)
What’s the slope of a d vs t graph and a v vs t graph?
Slope of distance vs. time graph denotes speed; Slope of displacement vs. time graph denotes velocity
What is the kinematic equation if you don’t know distance?
(vf)^2 - (vo)^2 = 2a(x)
What is the equation for distance vs time
d = v x t
What are equations for vertical and horizontal velocity given a specific angle? How do you find time from these values given distance?
Given Vo + angle + horizontal distance, FIRST calculate time to travel distance in horizontal direction using: Vox = vo (cos O), Voy = vo (sin O), and t = d (v) ——————- then use the equation: delt (y) = Voy(t) + 1/2 (a) t^2 to find distance traveled
What is the equation for the force of static friction?
The force of static friction will oppose the applied force by an equal amount if it is smaller than max static force
What is the equation for Torque?
Torque = F (d) sin O ———— Max Torque at 90 degrees
What is the equation for Work?
Work = F (d) cos O ———— Max Work at 0 degrees
How do you find Tension from Torque? What is the equation for Torque? What are units of each?
Tension = Torque / distance ——————————————– Units for Torque are N x m; Units for Tension are Newtons
What is the equation for horizontal force and vertical force, respectively?
Horizontal Tension: Fx = F (cos O)
What are the units of Mass and Weight, respectively?
Mass is in kg, Weight is in Newtons
What is the difference between Rotation and Translation?
Torques cause rotation of an object, often around a hinge; This causes the center of mass of the object to be displaced, which is termed Translation
What is the equation for conservation of energy when no non-conversative forces are acting?
Equation for conservation of energy when no non-conservative forces are acting: ————————- 1/2m(vi)^2 + mg(hi) = 1/2m(vf)^2 + mg(hf)
What is the equation for work with regards to pressure and volume?
Work = Pressure x (Change in Volume) ——————————— **If no change in volume, no work is done
How does the expansion of gas in a balloon affect the temperature inside the balloon? Why?
During expansion, gas performs work on its surrounding, which requires energy. Because energy is lost from the surrounding, temperature will decrease
What is the equation for KE of an ideal gas? What is the equation for Root mean square Velocity?
KE = 1/2m(v-rms)^2; v-rms = radical (3RT/Mm) –> T in Kelvin, R is ideal gas constant, Mm is molar mass KE = (3/2)T(R x m / Mm)
What is the Zeroth Law?
Zeroth Law = If one system is in thermal equilibrium with 2 other systems, then the other 2 systems must also be in thermal equilibrium with each other
What are the characteristics of a Closed Thermodynamic System?
Closed Thermodynamic System = System that can exchange energy, but not matter, with its surroundings
What is the equation for change in internal energy of a substance, considering the loss of heat?
delt(Energy) = Q - W —————————————- *Q = Heat, W = Work
Who do the following terms mean: Isobaric, Adiabatic, Isothermic, Isochoric?
Isobaric = Pressure Constant, Isothermic = Temp constant, Adiabatic = No heat or matter transferred, Isochoric = Same volume
What is the conversion from Joules to Calories?
4.18 J = 1 calorie
What is the unit for dietary calories?
The unit for dietary calories (Cal) is kilocalories
What processes are used to transfer heat into the body when Ambient temp > Physiological temp? What about cooling the body at high Ambient temperatures?
Ambient Temp > Physiological Temp: Radiation, conduction, and convection transfer heat into the body (Increased body temp) ——————————————– Ambient Temp > 37 C: Evaporation of sweat from skin and evaporative cooling from exhaled moisture transfer heat out of body and cool the body
What is the equation for absolute pressure?
Absolute pressure = Atmospheric pressure + Gauge pressure –> Pabs = Patm + pgh
What is the relationship between cross-sectional area and fluid velocity for an ideal fluid?
Continuity equation for ideal fluids: v1 x A1 = v2 x A2
What are the requirements for a fluid to be considered ideal?
Requirements for fluid to be considered ideal: Fluid and walls of container do not interact, fluid is not viscous, fluid exhibits laminar flow
What are cohesion and adhesion? How do an increase in each of these forces influence the shape of the meniscus?
Cohesion = Intermolecular interactions within a fluid, Adhesion = Interactions between a fluid and its container ———————————– *Stronger cohesive forces increase surface tension, which promotes convex shaped meniscus *Stronger adhesive forces –> Promotes increasingly concave meniscus
What is Bernoulli’s equation?
Bernoulli’s equation: P1 + 1/2p(v1)^2 + pg(h1) = P2 + 1/2p(v2)^2 + pg(h2)
What is the equation for % of an object’s volume that is submerged in a liquid?
% Submerged = (p-object)/(p-liquid) x 100
How does Increased pressure affect the rate of reaction for a mixture held at equilibrium?
Increased Pressure = Favors side of reaction with Less moles
What is the equation for delta G of a reaction?
delt(G) = delt(H) - T(delt S)
How does a Catalyst affect the rate of reaction?
A catalyst affects the kinetics of a reaction by lowering the activation energy of a reaction –> Increases the rate of both the forward and reverse reactions
What substances can and cannot be included in an equilibrium constant expression?
Solids and pure liquids should not be included in an equilibrium constant expression
How do you determine whether entropy increases/decreases in a given reaction?
If products and reactants are the same substance, entropy decreases in the direction with fewer molecules
What are the Energy diagram characteristics of a thermodynamically favorable, kinetically hindered reaction?
Thermodynamically Favorable, Kinetically Hindered = Large activation energy, Products are more stable / have lower free energy than Reactants
What is the effect of a shift in color of the reagents on Entropy of a reaction?
Color changes of reagents are associated with changes in their electronic structures, and do not correlate with shifts in Entropy
What is the equation for Electrostatic Potential Energy?
Electrostatic Potential Energy: U = qV
What is the equation for Resistance?
Resistance: R = p (L / A)
What is the equation for Electric Potential?
Electric Potential = k Q1 / R
What is the continuity equation that relates cross-sectional area to velocity?
v1 x A1 = v2 x A2
What is Poiseuille’s Law?
Poiseuille’s Law: Q = πr4ΔP/8ηL ——————————————– *Predicts linear relationship between flow rate (Q) and pressure loss (delt P)
What is the equation for Capacitance?
Capacitance = [k (Eo) A] / d
What are the equations to calculate Equivalent Capacitance for a circuit with Capacitors both in series and parallel?
Series: 1/Ceq = V1/Q + V2/Q… Parallel: Ceq = Q/V1 + Q/V2…
What is the equation for Power dissipated by a single resistor?
Power dissipated by a single resistor: P = (I)^2 x R
What is the equation for work done to charge a capacitor?
Work done to charge a capacitor: W = 1/2 (C) V^2
What is the equation for equivalent Capacitance in parallel and in series?
Parallel –> Ceq = C1 + C2… Series –> 1/Ceq = 1/C1 + 1/C2…
What is Conductance? What are the units of Conductance?
Conductance = Measure of ease with which current flows through a conductor —> Inverse of Resistance —————————————- Units = C^2/J s = (C^2) s / kg (m^2)
What are the equations for Capacitance and the Electric Field between the plates of a capacitor? How would introducing a dielectric affect the capacitance?
Capacitance –> C = Q / V ————————————— Electric Field b/w plates of a capacitor –> V = E d **A dielectric decreases E, which decreases V, which increases C
What is the equation for Period of a mass on a pendulum? What is the relationship between period and frequency?
Equation for Period of a Mass on a Pendulum: T=2π √(L/g) ———————————- Frequency = 1/T
How does Velocity, Wavelength, and Frequency change when a sound wave travels from air into a solid medium?
When a sound wave travels from air into a solid medium, its Velocity increases, its Wavelength increases, and the Frequency is not expected to change
Which of the following are accurate representations for units of Intensity of a sound wave: W/m^2, kg s^3, Db?
All of the following are accurate representations for units of Intensity of a sound wave: Decibels, W/m^2, kg s^3
What is the equation for Intensity of a sound wave?
Intensity: dB = 10 log (I / Io)
What is the Doppler Equation?
Doppler Equation: f’ = fo (Vsound + Vobserver) / (Vsound + Vsource)
What types of waves are Ultraviolet and Ultrasound waves, respectively?
Ultraviolet = Transverse waves, Ultrasound = Longitudinal waves
What factor primarily determines the speed of sound through a medium? What is the equation for velocity of sound through a specific medium? Will sound travel faster or slower through stiff materials?
Speed of sound through a medium is primarily determined by the Bulk Modulus of that material –> Stiffer materials = Higher bulk modulus = Sound waves move faster through stiffer materials
How do wavelengths, frequency, and energy compare between IR and UV radiation? What are approximate wavelengths?
IR radiation (wavelength b/w 10^(-4) to 10^(-6) = Lower frequency, Lower energy THAN UV Radiation (wavelength b/w 10^(-7) and 10^(-8)m
How does light change when traveling from a medium of lower to higher refractive index (n)?
Low to High refractive index (n) –> Light refracts/bends toward the normal (Smaller Angle of Refraction than Angle of Incidence)
What is the description of a mirror with a focal length of -2 m?
Focal Length < 0 –> Diverging Mirror (Convex) and always forms Virtual Images
What are the thin-lens and magnification equations?
Thin-lens Equation: 1/o + 1/i = 1/f Magnification: m = -i / o
What are the equations for focal length from radius and lens power? What are the units of lens power?
Focal Length = 1/2 (Radius) ———— Equation for Lens Power: P = 1/f (*Units = Diopters (1/m)
What type of lenses should be used to correct myopia? What about hyperopia? Focal lengths for each?
Myopia - Diverging Lens (f < 0) Hyperopia - Converging Lens (f > 0)
Under what conditions can a convex lens produce a virtual image? How about a real image? Also for concave lens?
Convex Lens (Converging): o < f –> Virtual image o > f –> Real, inverted image
How will increasing the distance between a laser pointer and the diffraction grating affect the brightness of light spots and the diameter of the laser beam, respectively?
Changing the distance between the laser and the diffraction grating does not change the brightness or diameter of the laser beam
How does changing light in diffraction experiment from Red Light to Blue Light influence spacing between bright spots?
Blue light has shorter wavelength than red light –> Direct relationship between wavelength of light and the sine of the angle of diffraction (d sin O = n * lambda) –> Spacing between diffraction spots decreases
What would be the velocity of a light beam in a vacuum be if the frequency of light is 100 MHz and it reflects off the diffraction grating?
All lights travels with the velocity of c = 3 x 10^8 m/s when in the vacuum of space
How does constructive and destructive interference affect bright spots that result from diffraction?
Constructive Interference = Creates bright spots at intervals next to the central spot (n=0) according to: (n) * Lambda = d sin(O) Destructive Interference = Creates dark regions separating the bright spots
What is the equation for wavelength that includes speed of light?
c = lambda * f
What are the units of Rate Constant (k)?
Units of the Rate Constant (k) = 1 / s * (M^2)
What is a Heterogeneous vs. Homogeneous catalyst?
Heterogeneous Catalyst = Catalyst that is in a different phase than the reactants
Which linear graphs indicate specific orders of reactions? (Zero, First, Second)
*Zero Order = [R] vs. Time –> Linear *First Order = ln [R] vs. Time –> Linear *Second Order = 1/[R] vs. Time –> Linear
How can the rate law of an elementary reaction be determined?
Rate law of elementary reaction (one-step) can be determined from looking at the balanced reaction –> Only reactants are included; Each raised to power of its coefficient
How can you determine entropy change in a given reaction?
When asked about entropy in a given reaction, first look to phase changes –> If reactants and products are the same phase, entropy will favor the side with more moles (Same number of moles = Zero entropy change)
What is the rate law of a Zero Order Reaction? What plot in zero order reaction will be a straight line?
Zero Order Reaction: *Rate Law = k *Plot of reactant concentration over time will be a straight line (Slope of Line = -k)
Which plots of Second Order reactions will have a straight line? Which will have a curved line?
Second Order Reactions: *Plot of 1/[A] vs. time is straight line (k = slope of line) *Plot of [A] vs. time or ln[A] vs. time will be curved
What is the photoelectric effect?
Photoelectric effect = Photoelectrons will only be ejected from metal plate when the frequency of incident light corresponds to energy required to overcome work function of metal (More intensity –> More photons incident on plane)
What is the principal attractive force within the nucleus?
Strong nuclear force = Principal attractive force responsibile for holding the nucleus together
What is the effect of alpha decay if ingested in human body? What is charge of alpha particle?
Alpha decay is exceedingly harmful if ingested or inhaled (Chage of alpha particle: +2)
What are a mutagen and teratogen, respectively?
*Mutagen = Any substance that causes a genetic change *Teratogen = Any substance that causes a malformation of an embryo
What are some characteristics of the particle in a mass spectrometer?
Charged, Moving at constant velocity, all have same velocity
How do the following units of pressure compare in value: atm, mm Hg, Pa?
1 atm = 760 mm Hg = 10^5 Pa
How do you use energy to calculate the final velocity of an object in free fall?
Conservation of Energy: KE = PE –> 1/2m(Vfinal)^2 = mgh
What type of regulation with O2 and hemoglobin causes a sigmoidal curve in the graph? What is O2 role in relation to hemoglobin?
Homotropic Regulation: Molecule serves as a substrate for its target enzyme, as well as a regulatory molecule of the enzyme’s activity (O2 is homotropic allosteric modulator of hemoglobin) —-> Cooperative binding = As each O2 binds to Hb, the affinity of Hb for O2 goes up (Cause of sigmoidal curve in graph)
What are the 6 phase changes?
Phase Changs: Deposition (gas to solid), Sublimation (solid to gas), Melting or Fusion (solid to liquid), evaporation (liquid to gas), freezing (liquid to solid), condensation (gas to liquid)
How does temperature and altitude affect the ability of air to hold H2O?
Decreasing temp, Higher altitude –> Air is able to hold less H2O
How much volume does each mole of gas occupy at STP?
1 mol = 22.4 L
What is Phenolphthalein and what is its function? What is its pKa and why does this matter?
Phenolphthalein = Indicator in acid-base titrations; functions to identify that an expected pH (titration endpoint) has been reached via color change or similar mechanism — pKa = 9.3 (must be +/- 1 unit of target pH)
List the 20 amino acids and their single-letter abbreviations
Glycine (Gly, G), alanine (Ala, A), valine (Val, V), leucine (Leu, L), isoleucine (Ile, I), methionine (Met, M), proline (Pro, P), serine (Ser, S), threonine (Thr, T), cysteine (Cys, C), Asparagine (Asn, N), Glutamine (Gln, Q), Tyrosine (Tyr, Y), Phenylalanine (Phe, F), Tryptophan (Trp, W), Histidine (His, H), Arginine (Arg, R), Lysine (Lys, K), Aspartate (Asp, D), Glutamate (Glu, E)
What are the structures of the following functional groups: Amide, Amine, Imine, Thioether, Ester, Acid Anhydride
*Amide: R-(C=O)-N-R2 *Amine: R-N-R2 *Imine: C=N *Thioether: R-S-R *Ester: R-(C=O)-O-R’ *Acid Anhydride: R(C=O)-O-(C=O)R’
What are the 2 types of isomers? Give definition of each
1) Structural Isomers = Different ways that atoms in a compound can be connected 2) Stereoisomers = Different ways substituents can be positioned (Cis/trans isomerism of alkene bonds)
What is the equation(s) for power? What are the units of power?
Power = W / t = Fv = IV *Units: Watts = J/s
What is the equation for energy of a photon related to its wavelength?
Energy = hc / Lambda
What is extraction?
Extraction = Technique used to separate 2 or more compounds in solution by manipulating the solubility properties using acid-base chemistry (separates polar vs. nonpolar compounds)
If a child is riding on a merry-go-round, what equations are needed to find the force required to keep child on the ride? Given = Radius of merry-go-round, Frequency
*Period: T = 1/f *Speed: V = 2(pi)R / T *Centripetal Acceleration: a = v^2/R *Centripetal Force: Fc = mv^2 / R
What is noncompetitive inhibition, uncompetitive inhibition, and suicide inhibition?
*Noncompetitive Inhibition = Inhibitor reduces enzyme activity by binding to an allosteric site (Km same, Vmax lower) *Uncompetitive Inhibition = Inhibitor binds to only the enzyme-substrate complex and inactivates it (Km and Vmax lower) *Suicide Inhibition = Enzyme binds the inhibitor and forms an irreversible complex with it, usually through covalent bond
What is isoelectric point? Equation?
Isoelectric Point = pH at which net charge of amino acid is zero ———- *pI = 1/2 (pKa1 + pKa2)
What are the equations for the forces acting on a gurney held on an inclined plane with static friction?
Fslide = mg (sin O) Fstatic = uFn = umg(cos O) Fnet = mg(sinO) - umg(cos O)
What is Rf in chromatography?
Rf = Distance the compound of interest traveled along the TLC plate divided by the distance traveled by the solvent front
How do kPa and J/L compare in values?
100 kPa = 100 J/L
What is Laminar Flow? What is Poiseuille’s Law and when is it used?
*Laminar Flow = Composed of parallel layers that may be moving at diff velocities *Poiseuille’s Law: Used to describe laminar flow of incompressible fluids through long cylindrical tube *Q = [pi(R^4)P] / 8nL —— P = Pressure drop between tube ends, n = viscosity)
What is Bernoulli’s Equation?
*Bernoulli’s Equation = Conversion of energy for fluids –> P1 +1/2p(v1)^2 + pg(h1) = P2 +1/2p(v2)^2 + pg(h2)
What is the continuity equation?
Continuity Equation: v1A1 = v2A2
According to Bernoulli’s equation, what happens to a volume of pressurized blood opened to the atmosphere?
A volume of pressurized blood opened to the atmosphere will convert its pressure to Kinetic Energy, rapidly exiting the body and causing shock
What is the equation for flow rate?
Flow Rate = (Cross-sectional Area) x (Velocity)
What is the function of Pyruvate Dehydrogenase?
Pyrvuate Dehydrogenase = Enzyme that mediates pyruvate decarboxylation, which converts 3C pyruvate into 2C acetyl-CoA + NADH + CO2 (this step is critical link between anaeroic and aerobic respiration)
What is the formula and molecular structure of hydrogen sulfide?
Hydrogen Sulfide = H2S, Bent
What is the function of pulmonary surfactant?
Pulmonary Surfactant = Adsorbs to the air-water-alevoli interface, reducing surface tension and the total force resisting expansion –> Decreases pressure difference and work required to inflate the airway
What is the range of wavelengths of visible light? Colors associated with each value?
400 nm (Blue) - 700 nm (Red)
In Rutherford’s experiment, what are the charges of the alpha particles and the gold nuclei, respectively? What is the consequence of these charges?
Both positive charges; Deflections were caused by electrostatic repulsion of positive charges
After 50 years, how much atomic mass is remaining following Beta decay (half life = 5 years)?
The atomic mass lost in Beta decay is negligible
What equation should be used when trying to find velocity of a crate that starts at rest and is pushed across a surface given the following variables: Mass, acceleration, distance?
(vf)^2 = (v0)^2 + 1/2 (a) d
Hybridization of imine nitrogen and carbonyl carbon?
Imine N = sp2, Carbonyl C = sp2
R vs. S !
Get down R vs S
Calculations to find yield
Know how to find limiting reagent and determine theoretical yield
What is the net charge of Phenylalanine at a pH of 1?
Net charge = +1
What is the equation for potential energy?
PE = mgh = 1/2k(x)^2
How does decreasing the volume of a system influence the equilibrium?
Decrease volume –> Shift eq to side with less moles
What is the equation for gauge pressure? What is the equation for absolute pressure?
P = pgy —– p = density of fluid, y = depth of object, g = gravity ———- 1 atm = 101,500 Pa ————— Pabs = Pgauge + Patm
What forces result in a concave meniscus? Definitions of adhesive and cohesive?
*Concave meniscus = Adhesive forces between fluid and glass are greater than cohesive foces between fluid particles; Adhesive = Attraction of 2 diff particles; Cohesive = Attraction of 2 like particles
Student assumes 2 fluids are ideal. Fluid A has negligible viscosity and moderately compressible. Fluid B has moderate viscosity and incompressible. How would calculations using the continuity and Bernoulli’s equation be affected in both scenarios? Why?
*Fluid A = Miscalculate continuity equation, which relates much more to compressibility than viscosity; A fluid must be incompressible to have a constant volume flow rate *Fluid B = Miscalculate Bernoulli’s equation, which relates much more to viscosity (internal friction of fluid) than compressibility; Viscous fluids are subject to nonconservative forces (not ideal)
If two ends of a system are subject to atmospheric pressure, how would Bernoulli’s equation be written?
Velocity = SQRT(2)*gh
What is the continuity equation?
A1V1 = A2V2
What is the equation for kinetic energy of a fluid given its velocity and volume?
KE fluid = 1/2(Volume)p(v)^2 ————————————————- p = density of fluid, v = velocity; 1 cm^3 = 1x10^(-6) m^3
What is sublimation? Deposition?
Sublimation = Solid to Gas Deposition = Gas to Solid
What is the equation for specific heat? What about for specific heat in cases of phase transitions?
*Q = mc(delt T) when Temperature is changing ———————————— *For phase transitions, Q = mL —— L = Latent heat of substance (Hvap or Hfusion)
What is the equation for freezing point depression?
ΔTf = Kfmi —- Kf = constant, m = molality, i = Van’t Hoff factor (number of dissolved particles per molecule)
What is the effect of adding PCC to alcohols?
*Primary alcohol –> Aldehyde *Secondary alcohol –> Ketone *PCC = Weak oxidizing agent
How do CrO3 and K2Cr2O7 affect reactions with alcohols?
CrO3 and K2Cr2O7 = Strong oxidants (Primary alcohol –> COOH)
What is the equation for the frequency of oscillation of a spring system?
f = 1/2 π [√(k/m)]
Which law accurately describes the reason that contraction of the diaphragm causes inhalation?
Boyle’s Law (PV = constant)
What is Charles’ Law
Charles’ Law (Direct relationship between V and T when P and n are fixed)
What is the Gay-Lussac Law
Gay-Lussac’s Law (Direct relationship between P and T when V and n are fixed)
What is Avogadro’s Law
Avogadro’s Law (Direct relationship between V and n when P and T are fixed)
What is the equation for solubility?
Henry’s Law (H = c/P) —————- Units: μmol/L•atm
How do increased levels of NADH affect glucose production and why?
Rate of glucose production (gluconeogenesis) in the liver will decrease (High NADH decreases future production of OAA and pyruvate –> Pyruvate production coupled with conversion of NAD+ to NADH and OAA is produced from pyruvate
What is gluconeogenesis? Where does it take place?
Conversion of pyruvate innto glucose – Takes place in both the mitochondria and cytosol
How do you calculate capacitance in a parallel circuit?
For parallel circuits, Ceq = C1 + C2 + C3…
What is the inductive effect? How does the inductive effect influence basicity?
Inductive Effect = Increases the availability of electron charge density available to donate, increasing basicity; This effect is caused by addition of an electron-donating group, like a methyl group
How do you calculate efficiency of an engine?
*Efficiency = Output work / Input energy *η (efficiency) = W/Qh
Units of Boltzmann constant (k)?
J/K = (m2•kg) / (s2•K)
What does adiabatic expansion?
No heat exchange + increased volume
How do polar vs. nonpolar compounds travel differently on TLC plate? How does solvent polarity affect eluting strength?
Polar compounds move slower on TLC plates; Eluting strength increases with increasing solvent polarity
What is normality in the context of acids?
Normality = Refers to the number of moles of protons per liter of solution (Molarity of protons); Calculate by multiplying molarity by the # of protons per molecule of acid
How many electrons are needed to classify a molecule as aromatic? Antiaromatic?
*Aromatic = 4n + 2 Pi electrons *Antiaromatic = 4n Pi electrons
What is the IC50 value?
IC50 = Concentration of inhibitor that reduces the activity of the corresponding process by 50%
What is the equation for Velocity of a wave?
V = (Gamma) x f
