PHYSICAL CHEMISTRY Flashcards
An ideal gas will only be considered in the
following operating parameters:
a. High Temperature, High Pressure
b. High Temperature, Low Pressure
c. Low Temperature, High Pressure
d. Low Temperature, Low Pressure
b. High Temperature, Low Pressure
Which ofthe following isfalse regarding absolute
zero?
a. All molecules will stop moving
b. Absolute zero can be achieved
c. Temperature is 0K
d. Temperature is 0R
b. Absolute zero can be achieved
For a real gas, what causes the deviation from
the ideal pressure at a molecular level?
a. Energy is lost for each collision against
the sides of the container
b. Energy is lost due to the collision of
molecules with one another
c. Intermolecularforces of attraction of the
molecules with one another
d. Molecules randomly hit the sides of the
wall with less force than usual
c. Intermolecularforces of attraction of the
molecules with one another
When gas molecules collide, they experience
collision.
a. Perfectly elastic c. Perfectly inelastic
b. Imperfect elastic d. Imperfect inelastic
a. Perfectly elastic
Which of the following is false with KMT?
a. Gas molecules move in random motion
b. Due to collision of gas molecules with
each other, some kinetic energy is lost
c. The temperature of the whole system
does not change with time
d. The size of the molecules are negligible
b. Due to collision of gas molecules with
each other, some kinetic energy is lost
Thisisthe pressure exerted by the gas molecules
that are in equilibrium with the liquid.
a. Partial pressure c. Total pressure
b. Atmospheric pressure d. Vapor pressure
d. Vapor pressure
The internal energy of an ideal gas depends on:
a. Volume c. Pressure
b. Absolute temperature d. Number of moles
b. Absolute temperature
Which of the following is a characteristic of an
adiabatic process?
a. ΔU=0 c. Q=0
b. W=0 d. ΔV=0
c. Q=0
Which of the following is not conserved in any
process?
a. Mass c. Momentum
b. Energy d. Entropy
d. Entropy
An isentropic process is:
a. Isothermal and adiabatic
b. Reversible and isothermal
c. Reversible and adiabatic
d. Reversible and isochoric
c. Reversible and adiabatic
Increasing the temperature of the cold reservoir
the Carnot efficiency.
a. Increases
b. Decreases
c. Does not change
d. NOTA
b. Decreases
If the entropy of a system decreases,the entropy
of its surroundings
a. Must always increase
b. Must always decrease
c. May increase or decrease
d. Not enough information to answer the question
a. Must always increase
The amount of heat absorbed when CO2 gas
reacts with a solid CaO to form solid CaCO3 is
measured in a bomb calorimeter. The data
obtained give a direct measure of:
a. ΔU
b. VΔP
c. ΔH
d. CP
a. ΔU
Heat required to raise the temperature of 1lbm
of water by 1˚F.
a. Calorie
b. BTU
c. Specific heat
d. Heat capacity
b. BTU
The general statement of the Third Law of Thermodynamicsis attributed to:
a. Nikolaus Otto
b. Jacobus Clapeyron
c. William Clausius
d. Walther Nernst
d. Walther Nernst
The equilibrium intensive state of a system is described by specifying the temperature, pressure, and:
a. Mole fractions
b. Number of moles
c. Volume
d. Chemical potential
a. Mole fractions
The fugacity of a real gas is equal to:
a. The pressure of an ideal gas which has
the same chemical potential as the real gas
b. The pressure of a real gas which has the same chemical potential as the ideal gas
c. The chemical potential of an ideal gas which has the same pressure as the real gas
d. The chemical potential of a real gas which has the same pressure as the idea gas
a. The pressure of an ideal gas which has the same chemical potential as the real gas
An adiabatic process is one in which the system
under investigation is thermally isolated so that
there is no exchange of heat with the
surroundings. Thus, the work done on a closed
system in an adiabatic process is _.
a. Equal to zero
b. Not equal to the exchange of heat with
surroundings
c. Equal to the increase in internal energy
of the system
d. Not equal to the increase in internal
energy of the system
c. Equal to the increase in internal energy
of the system
State Le Chatelier’s Principle.
a. Le Chatelier’s principle states that when
a stress is placed on a system in
equilibrium, the system tends to change
in a way that relieves the stress.
b. All of these
c. Examples of the application of Le
Chatelier’s principle are blowing your
breath through a straw and dissolving
alka seltzer tablet in a glass of water.
d. Le Chatelier’s principle explains both the
formation and decomposition of acids,
where anything that might act to
increase the concentration of an acid
would produce an increase in the other
components so as to keep the numerical
a. Le Chatelier’s principle states that when
a stress is placed on a system in
equilibrium, the system tends to change
in a way that relieves the stress.
Conceptual Question (Oct. 2021 PBE)
Determine which of the following occurrences
tells us what happens when Le Chatelier’s
principle is applied whether these are true or
false.
1. The addition of a component causes the
equilibrium to shift to the opposite side
2. The removal of a component causes the
equilibrium to the side from which the
component is removed
3. Increasing the temperature drives an
exothermic reaction to the side of the
reactants, an endothermic equilibrium
to the side of the products
4. The addition of a catalyst has NO effect
on the position of the equilibrium
a. T, F, T, F
b. T, T, T, T
c. F, T, F, T
d. F, F, F, F
b. T, T, T, T
Conceptual Question (Nov. 2019 PBE)
Define entropy.
a. Entropy is a function of the state of the
system and determines whether a
physical change or chemical reaction can
occur simultaneously in a closed system
b. Entropy is the opposite of enthalpy
c. Entropy determines the time required
for a reaction to proceed and complete
d. All of these
d. All of these
Conceptual Question (Oct. 2021 PBE)
Determine whether the changes in entropy (ΔS)
and enthalpy (ΔH) are positive, negative, or near
zero.
1. Ethyl alcohol evaporating from glass
container
2. A diatomic molecule dissociates into
atoms
3. Charcoal is burned to form CO2 and
water
a. 1. ΔH>0, ΔS>0; 2. ΔH>0, ΔS>0; 3. ΔH<0,
ΔS>0
b. 1. ΔH<0, ΔS<0; 2. ΔH>0, ΔS<0; 3. ΔH>0,
ΔS<0
c. 1. ΔH>0, ΔS<0; 2. ΔH<0, ΔS>0; 3. ΔH>0,
ΔS>0
d. 1. ΔH<0, ΔS>0; 2. ΔH<0, ΔS<0; 3. ΔH<0,
ΔS<0
a. 1. ΔH>0, ΔS>0; 2. ΔH>0, ΔS>0; 3. ΔH<0,
ΔS>0
Conceptual Question (Nov. 2019 PBE)
Choose the process that occurs with a decrease
in entropy.
a. Freezing of water
b. Boiling of water
c. Dissolving salt in water
d. Sublimation of dry ice
a. Freezing of water
It is the property of a fluid that is caused by
shearing effect of a fluid layer moving past
another layer.
a. Density c. Flow
b. Viscosity d. Compressibility
b. Viscosity
The Clapeyron Equation gives the slope:
a. dV/dT
b. dT/dP
c. dT/dV
d. dP/dT
d. dP/dT
The Clausius-Clapeyron Equation does NOT apply
to:
a. S-V equilibrium c. S-L equilibrium
b. L-V equilibrium d. None of these
S-L equilibrium
Conceptual Question (Nov. 2019 PBE)
What is the Clapeyron Equation?
a. Any of these
b. It postulates that the colligative properties, freezing point depression, boiling point elevation, osmotic
pressure, and vapor pressures are all dependent on the number f particles in
the solution and any change thereof is described.
c. It postulates that if two components systems consisting of solid and liquid
phases are miscible in the liquid state and immiscible in the solid state, only the pure solid systems will separate out on cooling solutions.
d. It postulates that if the temperature and pressure are both change in such a way as to keep the chemical potentials of two phases equal to each other, the rates of change are given by the equation.
d. It postulates that if the temperature and pressure are both change in such a way as to keep the chemical potentials of two phases equal to each other, the rates of change are given by the equation.
Conceptual Question (Oct. 2021 PBE)
The coexistence curve where the plot of pressure
versus temperature along which the two phases
coexist was shown by Clausius-Clapeyron. What
did Clausius postulate?
a. The Clapeyron equation was simplified by assuming that the vapor obeys the
ideal gaslaw and by neglecting the molar
volume of the liquid VL in comparison with the molar volume of the gas VG
b. The Clausius-Clapeyron equation does not
apply to this situation
c. The Clausius-Clapeyron theory is
applicable only for vaporization and
sublimation condition
d. Both scientists apply their postulates to
linear and curvilinear representation
a. The Clapeyron equation was simplified by assuming that the vapor obeys the
ideal gaslaw and by neglecting the molar
volume of the liquid VL in comparison with the molar volume of the gas VG
For miscible systems, the boiling point of the
solution is:
a. Lower than the boiling point of the liquid
with the lower boiling point
b. Between the boiling points of the two liquids
c. Above the boiling point of the liquid with
the higher boiling point
d. Cannot be determined
b. Between the boiling points of the two liquids
All colligative properties stem from the ____ of
the chemical potential of the liquid solvent as a result of the presence of the solute.
a. Reduction
b. Change
c. Enlargement
d. A or B or C, depending on the identities of the solute and solvent
a. Reduction
In a process involving osmosis, at equilibrium,
the chemical potential of the pure solvent side
should be the chemical potential of the
side with solute.
a. Less than
b. More than
c. Equal to
d. Can’t be determined
c. Equal to
When a solute is introduced to a liquid system, the
entropy of the said system:
a. Increases
b. Decreases
c. Stays the same
d. Can’t be determined
a. Increases
Among the following, which compound will
produce the least lowering of the vapor pressure
of a solution?
a. sucrose, C12H22O11
b. Aluminum chloride, AlCl3
c. Table salt, NaCl
d. Sodium sulfate, Na2SO4
a. sucrose, C12H22O11
Which of the following statements is true?
a. Trouton’s rule fails for highly polar
liquids
b. It is impossible to go from vapor phase
to liquid phase without condensation
c. For C compounds and P phases, there
are a total of CP intensive variables to be
specified
d. At high pressures, the latent heat of
vaporization is a measure of the strength
of the intermolecular forces of the liquid
a. Trouton’s rule fails for highly polar
liquids
Conceptual Question (Nov. 2019 PBE)
Are galvanic cells and electrolytic cells the same? Why?
a. No. because galvanic cells are electrochemical cells in which chemical cells occur spontaneously; while in electrolytic cells, the
chemical reaction is caused by an externally applied potential difference.
b. No, because galvanic cells need a constant supply of electricity while electrolytic cells depend on intermittent source of power.
c. Yes, because they are both electrochemical cells and their uses are common to each other
d. Yes, because galvanic cells and electrolytic cells are both
electrochemical cells.
a. No. because galvanic cells are electrochemical cells in which chemical cells occur spontaneously; while in electrolytic cells, the
chemical reaction is caused by an externally applied potential difference.
Conceptual Question (Nov. 2019 PBE)
What is the significance of colligative property in physical chemistry?
a. It refers to the freezing point depression, boiling point elevation, osmotic pressure and lowering of the vapor pressure by a nonvolatile solute
b. It refers to the temperature, pressure and energy of fusion of volatile solutes in phase equilibrium
c. It refers to the non-existence of pressure among molecules within the solute
d. It refers to the temperature differentials exhibited by non-volatile solutes in reactions
a. It refers to the freezing point depression, boiling point elevation, osmotic pressure and lowering of the vapor pressure by a nonvolatile solute
