Question 1

Which of the following processes is spontaneous under standard conditions? 
A. A raindrop falling to the ground 
B. Iron rusting in a moist atmosphere 
C. Water freezing at 25°C 
D. Dissolving NaCl in water at 25°C

Accepted Answer

A raindrop falling to the ground

Question 2

Arrange the following acids in order of increasing strength: 
HF(aq), HBr(aq), HI(aq) 
Which is the strongest acid?

Accepted Answer

HF \u003c HBr \u003c HI; HI is the strongest

Question 3

Given the following reaction: 
$$\mathrm{N_2$(g) + 3H_2(g) \rightarrow 2NH_3(g)} 
At 298 K$$, $$\Delta G^\circ = -33.2 kJ/$$mol. Is this reaction spontaneous under standard conditions?

Accepted Answer

Yes, because $$\Delta G^\circ is $$negative

Question 4

Which equation correctly relates the equilibrium constant $$K to $$the standard Gibbs free energy change $$\Delta G^\circ at $$temperature $$T$$?

Accepted Answer

$$\Delta G^\circ = -RT \ln K$$

Question 5

For the reaction $$\mathrm{CO_2$(g) + C(s) ightarrow 2CO(g)} at 298 K$$, the equilibrium constant $$K = 1.64 	imes 10$$^{-6}$$. What is the value of $$\Delta G^\circ$$ for this reaction at 298 K?

Accepted Answer

$$\Delta G^\circ = 32.8 kJ/$$mol

Question 6

Which of the following statements about entropy ($$S) is $$correct?

Accepted Answer

Entropy is a measure of the disorder or randomness of a system

Question 7

Consider the reaction $$\mathrm{N_2$(g) + 3H_2(g) \rightarrow 2NH_3(g)}. If $$the reaction quotient $$Q is $$less than the equilibrium constant $$K$$, in which direction will the reaction proceed?

Accepted Answer

The reaction will proceed in the forward direction

Question 8

Which of the following changes will increase the equilibrium constant $$K$$ for an endothermic reaction?

Accepted Answer

Increasing the temperature

Question 9

Given the reaction $$\mathrm{2SO_2(g) + O_2$(g) \rightarrow 2SO_3(g)}$$, which of the following will shift the equilibrium to the right?

Accepted Answer

Increasing the concentration of $$\mathrm{SO_2$}$$

Question 10

Which of the following is the correct mathematical expression for the reaction quotient $$Q$$ for the reaction $$\mathrm{2SO_2(g) + O_2$(g) \rightarrow 2SO_3(g)}$$?

Accepted Answer

$$Q = \dfrac{[SO_3$]^2}{[SO_2$]^2[O_2$]}$$

Question 11

A decrease in volume for the reaction $$\mathrm{N_2$(g) + 3H_2(g) \rightarrow 2NH_3(g)}$$ will have what effect on the equilibrium?

Accepted Answer

Shift equilibrium to the right (toward $$\mathrm{NH_3$})$$

Question 12

Which of the following is true about the relationship between $$\Delta G$$ and $$\Delta G^\circ$$?

Accepted Answer

$$\Delta G = \Delta G^\circ + RT \ln Q$$

Question 13

For the reaction $$\mathrm{2HgO(s) \rightarrow 2Hg(l) + O_2$(g)}$$, $$\Delta H = +182 kJ. $$How will an increase in temperature affect the equilibrium?

Accepted Answer

Shift equilibrium to the right

Question 14

Which of the following is the correct expression for the equilibrium constant $$K_p$$ for the reaction $$\mathrm{N_2O_4(g) \rightarrow 2NO_2(g)}$$?

Accepted Answer

$$K_p = \dfrac{(P_{NO_2$})^2$}{P_{N_2O_4}}$$

Question 15

If $$\Delta G^\circ$$ for a reaction is positive, what can be said about the equilibrium constant $$K$$?

Accepted Answer

$$K \u003c 1$$

Question 16

Which of the following is a correct statement about the effect of a catalyst on a chemical equilibrium?

Accepted Answer

A catalyst does not affect the position of equilibrium

Question 17

For the reaction $$\mathrm{$$CaCO_3$$(s) \rightarrow CaO(s) + CO_2$(g)}$$, which of the following will increase the amount of $$\mathrm{CO_2$}$$ produced at equilibrium?

Accepted Answer

Decreasing the pressure

Question 18

Which of the following is the correct formula for calculating $$\Delta G^\circ$$ from $$\Delta H^\circ$$ and $$\Delta S^\circ$$?

Accepted Answer

$$\Delta G^\circ = \Delta H^\circ - T \Delta S^\circ$$

Question 19

A reaction has $$\Delta H^\circ = -100 kJ $$and $$\Delta S^\circ = -200 J/K. At $$what temperature will the reaction become non-spontaneous?

Accepted Answer

$$T \u003e 500 K$$

Chemical Equilibrium and Thermodynamics: Study Notes and Key Equations

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