Question 1

Which statement best describes a spontaneous process in chemical thermodynamics?

Accepted Answer

It occurs without outside intervention and has a definite direction.

Question 2

Which of the following is true about the First Law of Thermodynamics?

Accepted Answer

Energy is conserved in all chemical processes.

Question 3

Consider the melting of ice at room temperature. Which thermodynamic factor primarily drives this spontaneous process?

Accepted Answer

Increase in entropy ($$\Delta S \u003e 0)$$

Question 4

Which equation correctly relates the change in entropy of the surroundings to enthalpy change at constant temperature?

Accepted Answer

$$\Delta S_{surr} = -\frac{\Delta H}{T}$$

Question 5

A process is reversible if:

Accepted Answer

It can go back and forth between states along the same path.

Question 6

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

Accepted Answer

Entropy is a measure of the disorder of a system.

Question 7

For a spontaneous process, what must be true about the entropy change of the universe ($$\Delta S_{univ}$$)?

Accepted Answer

$$\Delta S_{univ} \u003e 0$$

Question 8

Which process will result in the greatest increase in entropy?

Accepted Answer

Boiling water to form steam

Question 9

Which of the following correctly expresses the change in entropy for a system undergoing a reversible process at constant temperature?

Accepted Answer

$$\Delta S_{sys} = \frac{q_{rev}}{T}$$

Question 10

Which of the following is NOT a mode of atomic motion that contributes to entropy?

Accepted Answer

Ionization

Question 11

According to the Third Law of Thermodynamics, what is the entropy of a perfect crystal at 0 K?

Accepted Answer

It is zero.

Question 12

Which of the following reactions will result in a decrease in entropy?

Accepted Answer

2 NO(g) + O2(g) → 2 NO2(g)

Question 13

Which condition will always result in a spontaneous reaction according to Gibbs free energy?

Accepted Answer

$$\Delta H  0$$

Question 14

If $$\Delta G = 0$$ for a chemical reaction, what does this indicate?

Accepted Answer

The reaction is at equilibrium.

Question 15

Which equation relates Gibbs free energy change to enthalpy and entropy at constant temperature?

Accepted Answer

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

Question 16

Which of the following statements about standard molar entropy ($$S^\circ) is $$correct?

Accepted Answer

Standard molar entropy is measured in J/mol-K.

Question 17

For a reaction at equilibrium, which of the following is true?

Accepted Answer

$$\Delta G = 0$$

Question 18

Which of the following will increase the entropy of a system?

Accepted Answer

Increasing the temperature of a substance

Question 19

Which equation correctly relates the standard Gibbs free energy change to the equilibrium constant?

Accepted Answer

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

Question 20

Which of the following statements about exothermic and endothermic spontaneous processes is correct?

Accepted Answer

Endothermic processes can be spontaneous if they result in a significant increase in entropy.

Chemical Thermodynamics: Spontaneous Processes, Entropy, and the Second Law

Study Guide - Practice Questions