Blueprint Practice MCAT 1
Questions and Answers (Graded
A)
Adding salt to water causes the boiling point of the water to: - ANSWER - increase,
requiring a greater average kinetic energy of the liquid to produce a vapor pressure
equal to the external pressure
water is a rare substance in that the solid is less dense than the liquid at the
freezing point, resulting in a solid form that floats on top of the liquid. What best
explains this phenomenon? - ANSWER - the bent structure of the water molecule
and ratio of covalently-bonded hydrogens to lone pairs of electrons on the oxygen
atom maximized the hydrogen bonding that occurs in the solid phase, producing a
hexagonal structure with large empty spaces.
Another possible method of separating 2-methylundecanal and 2-methylundecanoic
acid could be based on:
A. their difference in the rotation of plane-polarized light
B. mass spectrometry analysis
C. an extraction based on their differing solubilities
D. they very different scent profiles of each molecule - ANSWER - C.
2-methylundecanoic acid has a carboxylic group which is much more soluble in
water than the aldehyde, causing it to have a higher solubility in aqueous solution.
Boiling chips and vacuum, distillation, respectively, are used in distillations to: -
ANSWER - provide nucleation sites that give the liquid a place to start forming
bubbles to prevent superheating; lower the boiling points of the substances to be
distilled.
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? - ANSWER - 20 m/s
, the mass starts with gravitational potential energy:
PE = mgh = 10kg(10m/s)20m = 2000J
the maximum speed is achieved just before impact when all of that potential energy
is converted to kinetic:
KE = 1/2mv^2
2000J=1/2(10kg)v^2
v=20 m/s
equation for torque - ANSWER - t=rFsin()
velocity equation - ANSWER - v=d/t
Given information provided in the passage, which of the following is the most likely
standard voltage change for the 1/2 O2/H20 redox pair?
A. +0.82
B. +0.14
C. -0.18
D. -0.45 - ANSWER - A.
O2 serves as the final electron acceptor of the ETC and must possess a standard
reduction potential that is more positive than any other acceptor in the chain. The
greatest potential listed is that of Fe3+/Fe2+ in cytochrome c, for which it is +0.22.
Only choice A exceeds this value.
A ray of white light moves through the air and strikes the surface of water in a
beaker. The index of refraction of the water is 1.33 and the angle of incidence is
30°. All of the following are true EXCEPT:
I. the angle of reflection is 30°
II. the angle of refraction is 30°
III. total internal reflection will result, depending on the critical angle
Questions and Answers (Graded
A)
Adding salt to water causes the boiling point of the water to: - ANSWER - increase,
requiring a greater average kinetic energy of the liquid to produce a vapor pressure
equal to the external pressure
water is a rare substance in that the solid is less dense than the liquid at the
freezing point, resulting in a solid form that floats on top of the liquid. What best
explains this phenomenon? - ANSWER - the bent structure of the water molecule
and ratio of covalently-bonded hydrogens to lone pairs of electrons on the oxygen
atom maximized the hydrogen bonding that occurs in the solid phase, producing a
hexagonal structure with large empty spaces.
Another possible method of separating 2-methylundecanal and 2-methylundecanoic
acid could be based on:
A. their difference in the rotation of plane-polarized light
B. mass spectrometry analysis
C. an extraction based on their differing solubilities
D. they very different scent profiles of each molecule - ANSWER - C.
2-methylundecanoic acid has a carboxylic group which is much more soluble in
water than the aldehyde, causing it to have a higher solubility in aqueous solution.
Boiling chips and vacuum, distillation, respectively, are used in distillations to: -
ANSWER - provide nucleation sites that give the liquid a place to start forming
bubbles to prevent superheating; lower the boiling points of the substances to be
distilled.
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? - ANSWER - 20 m/s
, the mass starts with gravitational potential energy:
PE = mgh = 10kg(10m/s)20m = 2000J
the maximum speed is achieved just before impact when all of that potential energy
is converted to kinetic:
KE = 1/2mv^2
2000J=1/2(10kg)v^2
v=20 m/s
equation for torque - ANSWER - t=rFsin()
velocity equation - ANSWER - v=d/t
Given information provided in the passage, which of the following is the most likely
standard voltage change for the 1/2 O2/H20 redox pair?
A. +0.82
B. +0.14
C. -0.18
D. -0.45 - ANSWER - A.
O2 serves as the final electron acceptor of the ETC and must possess a standard
reduction potential that is more positive than any other acceptor in the chain. The
greatest potential listed is that of Fe3+/Fe2+ in cytochrome c, for which it is +0.22.
Only choice A exceeds this value.
A ray of white light moves through the air and strikes the surface of water in a
beaker. The index of refraction of the water is 1.33 and the angle of incidence is
30°. All of the following are true EXCEPT:
I. the angle of reflection is 30°
II. the angle of refraction is 30°
III. total internal reflection will result, depending on the critical angle
