AAMC 4 - Chem/Phys Flashcards
Do acid-base reactions involve oxidation state changes?
No.
If one mole of gas has a volume of 22.4 L, what is the temperature and pressure it is in at that moment?
STP, which is defined as 273 K and 1 atm.
This is also 0 C and 101 kPa
What is the difference between data interpolation and extrapolation?
Interpolation is used to predict value between known data points.
Extrapolation is used to predict value outside the range of data.
Two vectors of magnitudes |A| = 8 units and |B| = 5 units make an angle that can vary from 0° to 180°. The magnitude of the resultant vector A + B CANNOT have the value of:
A. 2 units.
B. 5 units.
C. 8 units.
D. 12 units.
A. 2 units.
The magnitude of A + B is as small as 3 units (when A and B are anti-parallel and make an angle of 180°) and as large as 13 units (when A and B are parallel and make an angle of 0°). The magnitude of 2 units is smaller than the smallest possible magnitude of vector A + B.
What category of molecules exhibit london dispersion forces?
ALL real molecules exhibit london dispersion forces.
NH3 acts as a weak base in water with Kb = 1.76 × 10–5 at 25°C. The corresponding equilibrium is shown below.
NH3(aq) + H2O(l) ⇌ NH4+(aq) + OH–(aq)
At 25°C, the equilibrium concentration of the NH4+ ion in a 10 M aqueous solution of NH3 would be closest to which of the following?
A. 0.001 M
B. 0.01 M
C. 0.1 M
D. 1 M
B. 0.01 M
Find the equilibrium constant K, and set it equal to Kb so that:
Kb= [NH4+][OH-] / [NH3]
[NH3] = 10 M so multiply both Kb and the right side by 10 to get:
1.76 x 10-4 = [NH4+][OH-]
this is the same as:
1.76 x 10-4 = x2
solve for x
x = 1.25 x 10-2 or 0.01
Describe the relationship between the number of energy levels transitioned, change in energy, frequency, and wavelength.
The greater the number of energy levels transitioned between, the greater change in energy.
The greater change in energy, the higher the energy of the photon released or hf, so the greater change in energy, the greater increase in frequency.
The greater increase in frequency, the greater decrease in wavelength.
The arrows labeled 1–4 in the figure show several possible transitions between electron energy levels in a hydrogen atom.
Which transition produces a photon with the longest wavelength?
A. Transition 1
B. Transition 2
C. Transition 3
D. Transition 4
B. Transition 2
The separation between the energy level equals the energy of the photon. The energy of the photon is inversely proportional to the wavelength. The longest wavelength corresponds to the smallest photon energy, which corresponds to the transition between the closest energy levels.
What functional groups will LiAlH4 and NaBH4 reduce?
LiAlH4 and NaBH4 will reduce aldehydes and ketones.
What is the relationship between a ping-pong mechanism and a double-displacement mechanism?
They are the same thing
What is the relationship between a buffer’s buffering capacity, pH, and pKa?
A buffer has a buffering capacity that is ±1 pH unit away from the pKa
What is the equation for catalytic efficiency?
Kcat / Km
What is the relationship between Kcat and Vmax?
A directly proportional relationship
The higher the Kcat, the higher the Vmax
Suppose a defibrillator successfully returns a baby’s heart to normal beating. Suppose further that 20 g of blood enters the heart at 25 cm/s and leaves 0.10 s later at 35 cm/s. What is the estimated average force on the 20 g of blood as it moves through the baby’s heart?
A. 0.020 N
B. 0.20 N
C. 20 N
D. 2000 N
A. 0.020 N
According to Newton’s second law, the average force is equal to the mass of blood multiplied by the average acceleration of the blood. The average acceleration is:
(35 cm/s – 25 cm/s)/0.10 s
= 100 cm/s2 = 1 m/s2
The average force is 20 g × 1 m/s2
= 0.020 kg × 1 m/s2
= 0.020 N.
