Question 1

Which of the following best describes a closed system in thermodynamics?

Accepted Answer

A system that can exchange energy but not matter with its surroundings.

Question 2

According to the First Law of Thermodynamics, which statement is correct?

Accepted Answer

Energy that leaves a system is absorbed by the surroundings.

Question 3

Which equation correctly relates entropy $$(S) to $$heat energy $$(Q)$$ and temperature $$(T)$$?

Accepted Answer

$$S = Q \div T$$

Question 4

A spontaneous reaction is characterized by which of the following conditions?

Accepted Answer

$$\Delta G \u003c 0$$

Question 5

Which term describes the measure of how energy is dispersed within a system?

Accepted Answer

Entropy $$(S)$$

Question 6

During the combustion of a fatty acid in a bomb calorimeter, what is the sign of $$\Delta H$$ for the system (reaction)?

Accepted Answer

Negative, because heat is released by the system.

Question 7

Which of the following best explains why entropy tends to increase in an isolated system according to the Second Law of Thermodynamics?

Accepted Answer

Energy disperses and becomes more spread out over time.

Question 8

If a process is reversible and at equilibrium, what is the value of $$\Delta G$$?

Accepted Answer

$$\Delta G = 0$$

Question 9

Which of the following is true for an open system?

Accepted Answer

It can exchange both energy and matter with its surroundings.

Question 10

Which formula represents the relationship between Gibbs free energy, enthalpy, and entropy?

Accepted Answer

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

Question 11

Which of the following processes is most likely to be entropy-driven?

Accepted Answer

Dissolution of salt in water

Question 12

In a reaction, if $$\Delta H is $$positive and $$T\Delta S is $$also positive, under what condition will the reaction be spontaneous?

Accepted Answer

At high temperatures

Question 13

Which statement best describes enthalpy $$(H)$$?

Accepted Answer

It is the heat content of the system.

Question 14

A reaction has $$\Delta H = -100 kJ $$and $$T\Delta S = -20 kJ. $$What is $$\Delta G$$ for the reaction?

Accepted Answer

$$\Delta G = -80 kJ$$

Question 15

Which of the following is NOT a form of energy mentioned in the study materials?

Accepted Answer

Nuclear

Question 16

Which process is irreversible according to the study materials?

Accepted Answer

A process far from equilibrium with $$\Delta G$$ very negative

Question 17

Which of the following best describes the driving force for a process?

Accepted Answer

The process with the greatest increase in entropy and/or enthalpy

Question 18

In the context of entropy, which scenario represents a higher entropy state?

Accepted Answer

A gas with molecules dispersed throughout a container

Question 19

Which of the following statements about disorder and entropy is most accurate?

Accepted Answer

Entropy is commonly thought of as disorder, but it is better described as energy dispersal.

Question 20

If a reaction liberates heat and increases the dispersal of energy, which thermodynamic quantities are likely to be negative?

Accepted Answer

$$\Delta G$$ and $$\Delta H$$

Thermodynamics: Systems, Enthalpy, Entropy, and the Laws of Thermodynamics

Study Guide - Practice Questions