ACS CHEMISTRY GENERAL EXAM 2024 ACTUAL
EXAM 2 VERSIONS (VERSION A AND B)
COMPLETE 400 QUESTIONS WITH DETAILED
VERIFIED ANSWERS /ALREADY GRADED A
True or False? A spontaneous reaction is a fast reaction. - ANSWER False
True or False? Spontaneous processes proceed without outside intervention. -
ANSWER True
True or False? Only exothermic processes are spontaneous. - ANSWER False
True or False? Spontaneous processes require continuous addition of energy from
an external source. - ANSWER False
How does flexibility correlate to entropy? - ANSWER Greater conformational
flexibility correlates well with higher entropy
Two cubic containers have gas samples at the same temperature and pressure. One
container is larger than the other. Which has the higher entropy? Why? - ANSWER
The larger container has the higher entropy due to it having more particles
Which compound has the highest standard molar entropy (S^o)?
C3H8(g) C2H6(g) CH4(g) - ANSWER C3H8(g)
Which compound has the highest standard molar entropy (S^o)?
CCl4(l) CHCl3(l) CH2Cl2(l) - ANSWER CCl4(l)
Which compound has the highest standard molar entropy (S^o)?
CO2(l) CO2(g) CS2(g) - ANSWER CS2(g)
How are entropy and volume related? - ANSWER As volume increases, so does
entropy
Translational Motion - ANSWER Molecule travels from one location to another
Rotational Motion - ANSWER Molecule spins about an imaginary axis
Vibrational Motion - ANSWER Two atoms of a molecule move toward and away from
each other
The spontaneous reaction
A -> B + C
increases the system entropy by 132.0 J/(K & mol). What is the entropy change of
the surroundings? - ANSWER > 132.0 J/(K & mol)
, When entropy of the universe is positive, is the process spontaneous,
nonspontaneous, or at equilibrium? - ANSWER Spontaneous
When entropy of the universe is negative, is the process spontaneous,
nonspontaneous, or at equilibrium? - ANSWER Nonspontaneous
When entropy of the universe is 0, is the process spontaneous, nonspontaneous, or
at equilibrium? - ANSWER At equilibrium
What is the equation for calculating the system entropy for gas compression or
expansion? - ANSWER nRln((Vf)/(Vi))
If ΔG is less than 0, is the reaction spontaneous, nonspontaneous or at equilibrium?
- ANSWER Spontaneous in the forward direction and nonspontaneous in the reverse
direction
If ΔG is greater than 0, is the reaction spontaneous, nonspontaneous or at
equilibrium? - ANSWER Nonspontaneous in the forward direction and spontaneous
in the reverse direction
If ΔG is 0, is the reaction spontaneous, nonspontaneous or at equilibrium? -
ANSWER At equilibrium
When ΔHrxn is less than 0, is the reaction exothermic or endothermic? - ANSWER
Exothermic
When ΔHrxn is more than 0, is the reaction exothermic or endothermic? - ANSWER
Endothermic
If ΔH is negative and ΔS is positive, what is ΔG? Is the reaction spontaneous? -
ANSWER ΔG is always negative and the reaction is always spontaneous
If ΔH is positive and ΔS is negative, what is ΔG? Is the reaction spontaneous? -
ANSWER ΔG is always positive and the reaction is never spontaneous
If both ΔH and ΔS are negative, what is ΔG? Is the reaction spontaneous? -
ANSWER ΔG is negative at lower temperatures and the reaction is spontaneous at
lower temperatures
If both ΔH and ΔS are positive, what is ΔG? Is the reaction spontaneous? -
ANSWER ΔG is negative at higher temperatures and the reaction is spontaneous at
higher temperatures
Which step in a reaction is always the rate determining step? - ANSWER The slower
one
What will be the effect of increasing the temperature of reactants that are known to
undergo an endothermic reaction? - ANSWER Both the rate of reaction and the
value of the equilibrium constant increase
EXAM 2 VERSIONS (VERSION A AND B)
COMPLETE 400 QUESTIONS WITH DETAILED
VERIFIED ANSWERS /ALREADY GRADED A
True or False? A spontaneous reaction is a fast reaction. - ANSWER False
True or False? Spontaneous processes proceed without outside intervention. -
ANSWER True
True or False? Only exothermic processes are spontaneous. - ANSWER False
True or False? Spontaneous processes require continuous addition of energy from
an external source. - ANSWER False
How does flexibility correlate to entropy? - ANSWER Greater conformational
flexibility correlates well with higher entropy
Two cubic containers have gas samples at the same temperature and pressure. One
container is larger than the other. Which has the higher entropy? Why? - ANSWER
The larger container has the higher entropy due to it having more particles
Which compound has the highest standard molar entropy (S^o)?
C3H8(g) C2H6(g) CH4(g) - ANSWER C3H8(g)
Which compound has the highest standard molar entropy (S^o)?
CCl4(l) CHCl3(l) CH2Cl2(l) - ANSWER CCl4(l)
Which compound has the highest standard molar entropy (S^o)?
CO2(l) CO2(g) CS2(g) - ANSWER CS2(g)
How are entropy and volume related? - ANSWER As volume increases, so does
entropy
Translational Motion - ANSWER Molecule travels from one location to another
Rotational Motion - ANSWER Molecule spins about an imaginary axis
Vibrational Motion - ANSWER Two atoms of a molecule move toward and away from
each other
The spontaneous reaction
A -> B + C
increases the system entropy by 132.0 J/(K & mol). What is the entropy change of
the surroundings? - ANSWER > 132.0 J/(K & mol)
, When entropy of the universe is positive, is the process spontaneous,
nonspontaneous, or at equilibrium? - ANSWER Spontaneous
When entropy of the universe is negative, is the process spontaneous,
nonspontaneous, or at equilibrium? - ANSWER Nonspontaneous
When entropy of the universe is 0, is the process spontaneous, nonspontaneous, or
at equilibrium? - ANSWER At equilibrium
What is the equation for calculating the system entropy for gas compression or
expansion? - ANSWER nRln((Vf)/(Vi))
If ΔG is less than 0, is the reaction spontaneous, nonspontaneous or at equilibrium?
- ANSWER Spontaneous in the forward direction and nonspontaneous in the reverse
direction
If ΔG is greater than 0, is the reaction spontaneous, nonspontaneous or at
equilibrium? - ANSWER Nonspontaneous in the forward direction and spontaneous
in the reverse direction
If ΔG is 0, is the reaction spontaneous, nonspontaneous or at equilibrium? -
ANSWER At equilibrium
When ΔHrxn is less than 0, is the reaction exothermic or endothermic? - ANSWER
Exothermic
When ΔHrxn is more than 0, is the reaction exothermic or endothermic? - ANSWER
Endothermic
If ΔH is negative and ΔS is positive, what is ΔG? Is the reaction spontaneous? -
ANSWER ΔG is always negative and the reaction is always spontaneous
If ΔH is positive and ΔS is negative, what is ΔG? Is the reaction spontaneous? -
ANSWER ΔG is always positive and the reaction is never spontaneous
If both ΔH and ΔS are negative, what is ΔG? Is the reaction spontaneous? -
ANSWER ΔG is negative at lower temperatures and the reaction is spontaneous at
lower temperatures
If both ΔH and ΔS are positive, what is ΔG? Is the reaction spontaneous? -
ANSWER ΔG is negative at higher temperatures and the reaction is spontaneous at
higher temperatures
Which step in a reaction is always the rate determining step? - ANSWER The slower
one
What will be the effect of increasing the temperature of reactants that are known to
undergo an endothermic reaction? - ANSWER Both the rate of reaction and the
value of the equilibrium constant increase
