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MCAT Chem/Phys Review Test #9

Terms in this set (74)

As long as what is known can the flow rate be calculated through a wave or medium?
Velocity and a given area
What is the key when questions ask about flaws?
Look for the answer that most resembles a flaw, not the one that is just a true statement
In longitudinal waves, what is the direction of wave propagation?
It is parallel
How do particles in longitudinal waves vibrate?
They vibrate due to changes in pressure or collision of adjacent particles within an elastic medium
What contributes to wave propagation?
Particle vibration
What is the direction of wave propagation in traverse waves?
perpendicular to the normal
What is an example of a sterol lipid?
cholesterol because it is fused from a four ring core structure
What are glycerolipids comprised of?
mono-, di-, tri-substituted lipids
Will the mass of an object change when it is moved to a different area with a stronger gravitational pull?
No weight will change but not mass
When gamma particles are emitted, in which direction do they travel? What is the implication of this?
They travel in scattered differentiated paths which is why a localizer is always necessary to harness gamma related energy
What type of bonds are broken when a compound reaches the gas phase?
Intermolecular, INTAMOLECULAR FORCES ARE STILL PRESENT
What is a neat liquid?
It is the pure substance in the liquid phase
What is a Nujol mull?
It is a suspension of a finely ground solid in mineral oil, which is used for IR
What type of interaction is a hydrogen bond?
An intermolecular reaction
What is a characteristic of infrared spectra of alochols?
The tend to lack the sharp peak around -3700 due to the fact that the spectra is recorded as a neat liquid
What is a stretch in the -1700 range of IR associated with?
A carbonyl
What is the a stretch in the -3000 range that is broad associated with?
Carboxylic acids
What is a stretch in the 3300-3500 that is sharp associated with?
An O-H bond
What is a sharp peak (2) around 3400 indicative of?
N-H
What is a peak in the 2100-2200 range associated with?
C TB N or C TB C
Where are single bonded C-O stretches typically found?
1100-1000 cm -1
What to peaks that are present at atypical frequencies represent?
Impurities in the given substance
When hydrogen bonding is present in a give molecule, how does this impact IR spectra compared to when H bonding is not present?
When H bonding is present, there is a broader peak aroud the 3000 cm-1 area. When in gas phase, usually a sharper peak
Where are C-H stretches usually observed?
Just below 3000 cm -1
What is the stationary phase in regular HPLC?
Polar
What is the stationary phase in reverse HPLC?
Nonpolar
What is a way to remember the stationary phase of regular HPLC?
HPLC is like TLC, TLC has a polar stationary phase
What is a vital characteristic a compound needs in order to be analyzed using gas chromatography?
It needs to be able to be vaporized without being broken down or combusting for proper analysis in the gas phase
What is a key to eliminating certain answer choices?
Take away an answers that do not deliberately answer the question or that do not directly correlate to passage data
What is the best way to solve for time in a physics problem when given starting height and velocity?
x = vt
When can you assume there is no vertical component of velocity and set Vo = 0?
When there is horizontal velocity present
How would you solve for ending height of a baseball pitch? What variables would you need to know?
Time, acceleration (remember sign rule)

y = Vot + .5at^2

Then Subtract this value from starting height to get ending height
Under what conditions to deviation from the ideal gas law occur?
High pressure low temperature
What are two given assumptions we can make about ideal gas law particles?
Individual particles do not have volume, and there are no attractive or repulsive forces between gas particles
What condition of ideal gas law rules is broke under non-ideal conditions?
The particles now have a volume and interactions that need to be accounted for
High pressure is indicative of what as far as compression?
Higher pressure will compress the molecules more
What is a method to increase pressure in a given solution?
decrease volume
The higher the pressure does what in terms of the factor the volume will differentiate from the ideal?
The higher the pressure the more Vreal will deviate from Videal or Vpredicted
For one mole of ideal gas, what does the quantity of PV/RT equal?
It equals 1 for all pressures
When Vreal is higher than Videal, what will the ration of PV/nRT be equal to?
It will exceed 1
What are tautomers?
Isomers that differ around the position of protons and electrons
What can be assumed in structures that are tautomers of each other?
They will have the same carbon skeleton (Meaning no change or loss of functional groups)
Avoiding formal charge on atoms increases what?
Increases overall molecule stability
What kind of tautomer is more favorable, one that has an alkene or one with a carbonyl?
One that contains a carbonyl
Does conjugation effect stability?
The more conjugation the more stable
What is the difference between Go and G?
Go refers to free energy change under standard biological conditions, NOT equilibrum
When a biochemical reaction is at equilibrium, what can be assumed?
G = 0
What is the only condition under which Keq can equal ?
When there is no product formation at all, Keq=products/reactions so products would give the value a 0
What is the difference between Keq and Q?
Same in principle of calculation however Q can be used to calculate ratio of products to reactants at all stages, not just eq
When a process reaches eq, what is the value of Q?
Q = Keq
When Keq is greater than 1, what can be assumed about product and reactant stability?
When Keq is a LARGE number, we can assume products are very much preferred
When Keq is less than 1, what can be assumed?
That reactants are preferred and hence more stable
What is the reaction mechanism for the hydrolysis of pyrophosphate (PP)?
PP -> 2P
Using Hess's Law, what can information can be deduced and through what process?
By aggregating equations and flipping Go values, delta Go at a given temperature can be determined for a given set of reactants and products taken from each of the original starting equations
What is the Nernst equation?
E = Eo - 0.059/n logQ
In order to obtain the most positive E value possible, what change can be assessed?
We need to make Q more negative, therefore decreasing the ratio of products to reactants.
What is usually the reactant in an oxidation reduction reaction of interest?
The species being reduced serves as the reactant
If you increase the amount of oxidized species in solution, what will be the resultant effect on overall E?
High the ratio of logQ the more positive the value, and therefore the more negative E becomes
What is a positive E correlated with?
A spontaneous reaction
What is the formula for current?
I = P/V (voltage)
Strongly basic + weak acid = what type of solution
Weakly basic solution
What is the cos of 30 degrees?
sqrt 3 divided by 2
When a car is decelerating, what is the best way to find its acceleration give an angle?
Tan of the angle (sin/cos) * gravity (10 m/s)
If two substances in which one has a lower specific gravity, where will the force of impact be first in the brain?
The back of the skull is where the brain will hit first, because it is less dense
Greater density of CSF causes it to move in what direction upon braking of a car?
Forward toward the front of the brain because its specific gravity is greater than the surrounding environment.
How is molar density calculated?
formula mass of the element divided by the molar volume of any ideal gas
What is the molar volume of an ideal gas at STP?
22.4 L/mol
In order to accurately measure the density of a pure gas inside a balloon at STP what should be initially assumed?
Molar volume is 22.4 L and determine formula mass, process of elimination will be how you come to the correct answer
If two balloons composed of He and air gas respectively are analyzed, that is the difference between speed and molecule speed between the two balloons?
Molecule speed will be faster in He because if molecule speed's inverse relationship with mass. But the overall speed will be the same of both balloons because KE is dependent on T. Therefore same T conditions mean that the KE of both will be the same.
If a molecule has faster molecular particle movement, does this mean that the speed of another molecule will slower moving particles with be the same?
Only if the temperature in both systems are the same. Velocity depends on KE and KE is dependent on T
Are dipole dipole forces present between polar molecules?
No
What is induced dipole bonding?
Occurs only when a polar molecule induces a nonpolar molecule to become temporarily polar.
Lowest bond dissociation enthalpy is associated with what?
Best stabilization of intermediate free radical that results from the loss of a hydrogen atom
What stabilizes free electron radicals?
Electron donating species
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