Assessment Exam: Physical Chemistry
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For an ideal gas,
Z=PV
m
/RT
is unity. Which is true in general for a real gas?
A. Z = 1 for all pressures.
B. Z < 1 at low pressures and Z < 1 at hight pressures.
C. Z > 1 at low pressures and Z < 1 at hight pressures.
D. Z < 1 at low pressures and Z > 1 at hight pressures.
Which of these isotherms is experimentally observed near the critical temperature
of a real gas?
A.
B.
C.
D.
The enthalpy of water at 1 bar from 273 to 473 K is shown in the graph.
Which graph represents the constant pressure heat capacity?
A.
B.
C.
D.
Consider the P-V graph for reversible expansions. For given initial and final volumes and the same initial temperature, which statement describes the relative amount of work done?
A. Isothermal reversible expansion does less work.
B. Adiabatic reversible expansion does less work.
C. Both expansions do the same work.
D. Not enough information is provided in the graph to decide which expansion does more work.
Which plot best represents a possible variation of Ä G over time as a closed-system process involving only pressure-volume work at constant temperature and pressure approaches equilibrium in the forward direction?
A.
B.
C.
D.
To derive the integrated Clausius-Clapeyron equation,
ln(P
2
/P
2
) = -(
D
H
vap
/R)[(1/T
2
)-(1/T
1
)]
from the Clapeyron equation
dP
=
D
S
vap
dT
D
V
vap
which approximations are necessary?
A. The molar volume of the liquid is negligible compared to that of the vapor.
B. The vapor is an ideal gas.
C. The molar volume of the vapor is constant over the temperature range T
1
to T
2
.
D.
D
S
vap
is constant over the temperature range T
1
to T
2
.
E.
D
H
vap
is constant over the temperature range T
1
to T
2
.
The rate for: is rate = k[A][B]
2
. If [A]
o
= 1.0 M
and [B]
o
= 0.0010 M, then the rate law will be:
A + B --> C + D
A. pseudo-zeroth order.
B. pseudo-first order.
C. pseudo-second order.
D. pseudo-third order.
Consider the contour diagram corresponding to the potential energy surface for the
H + H
2
reaction when the three atoms (A, B and C) are constrained to be collinear.
The point X on the diagram corresponds to the:
A. steady state.
B. minimum energy state.
C. degenerate state.
D. transition state.
In heterogeneous catalysis of reactions on solid surfaces, the effectiveness of a given
catalyst is not determined by the:
A. bulk density of the catalyst.
B. surface roughness of the catalysts.
C. number of active sites on the catalyst surface.
D. degree of adsorption of the reactant on the catalyst surface.
The rate of a chemical reaction depends on the total number of collisions between reactant molecules. The total number of collisions is favored by:
A. smaller collison cross section and low molecular velocities.
B. smaller collision cross section and high molecular velocities.
C. larger collision cross section and low molecular velocities.
D. larger collision cross section and high molecular velocities.
For the two-state system shown, what is the ratio of the populations of the two states, N
2
/N
1
?
A.
B.
C.
D.
Select the graph that corresponds to the first order chemical reaction:
A ---> products
A.
B.
C.
D.
Which integral would be used to determine
x
2
when
y
(
x
) is a normalized wavefunction?
A. (integral
y
(
x
)*
y
(
x
)d
x
)
2
B. intergral
y
(
x
)*
x
2
y
(
x
)d
x
C. intergral
y
(
x
)*
y
(
x
)d
x
D.
x
2
intergral
y
(
x
)*
y
(
x
)d
x
What is the expectation value for position for the ground state eigenfunction of
a particle in a one-dimensional box extending from 0 to a?
A. 0
B. a/3
C. a/2
D. a
Suppose
y
is an eigenfunction of the Hamiltonian operator and
a
is the corresponding eigenvector. Which statement must be true?
A.
a
must be positive.
B.
a
must be negative.
C.
a
must be an integer.
D.
a
must be real.
What are the posible values of the term symbols for the excited state
of helium?
A.
1
S,
3
S
B.
2
S only.
C.
1
S,
3
P
D.
1
S only.
According to the Born interpretation, which is not a requirement for an acceptable wavefunction,
y
?
A.
y
must be a positive function.
B.
y
must finite everywhere.
C.
y
must have only one value at each point in space.
D.
y
must be a continuous function.
Which is an acceptable trial wavefunction for the ground state of helium,where a and b are spin wavefunctions?
A. }
y
1s
(1)
y
1s
(2)(1/2){
a
(1)
b
(2)-
b
(1)
a
(2)}
B. }
y
1s
(1)
y
1s
(2)(1/2){
a
(1)
b
(2)+
b
(1)
a
(2)}
C. }
y
1s
(1)
y
1s(2)
a
(1)
b
(2)
D. }
y
1s(1)
y
1s
(2)
a
(1)
a
(2)
Indentify the correct diagram for the four lowest energy levels of a hydrogen atom.
A. A
B. B
C. C
D. D