Unit 3. Reactions
V. Thermodynamics
Quiz 1
1.
If the equilibrium constant for the reaction above is greater than 1015, the standard voltage, E° and the standard free energy change, ΔG°, for this reaction is most likely.
E° and ΔG° are both zero
E° is negative and ΔG° is positive
E° and ΔG° are both negative
E° and ΔG° are both positive
E° is positive and ΔG° is negative
2.
Given the following information:
Find the enthalpy change for: 2 C(
s
) + H
2
(
g
) -> C
2
H
2
(
g
)
454.0 kJ
-227.0 kJ
0.0 kJ
227.0 kJ
-454.0 kJ
3.
A sample of gallium metal is sealed inside a well-insulated rigid container. The temperature inside the container is at the melting point of gallium metal. What can be said about the energy and the entropy of the system after equilibrium has been established. Assume the insulation prevents any energy change with the surroundings.
The total energy increases. The total entropy will increase.
The total energy is constant. The total entropy is constant.
The total energy is constant. The total entropy will decrease.
The total energy is constant. The total entropy will increase.
The total energy decreases. The total entropy will decrease.
4.
When ammonium chloride dissolves in water the temperature drops. Which of the following conclusions may be related to this?
The hydration energies of the ions are very high.
Ammonium chloride produces an ideal solution in water.
The heat of solution for ammonium chloride is exothermic.
Ammonium chloride has a low lattice energy.
Ammonium chloride is more soluble in hat water.
5.
Choose the reaction expected to have the greatest increase in entropy.
6.
Under standard conditions calcium metal reacts readily with chlorine gas. What conclusions may be drawn from that fact?
7.
Which of the following combinations is true when potassium bromide melts?
8.
Which of the following reactions have a negative entropy change?
I only
I, II and III
I and II
II only
III only
9.
From the table below, determine the enthalpy change for the above reaction.
0 kJ
485 kJ
-485 kJ
464 kJ
443 kJ
10.
Determine ΔH for the above reaction if CH
3
OH(
l
) were formed in the above reaction instead of CH
3
OH(
g
). The ΔH of vaporization for CH
3
OH is 37 kJ/mole.
-128 kJ
-54 kJ
+128 kJ
+54 kJ
-37 kJ
