Question 1

Which of the following best describes an endothermic process?

Accepted Answer

A process in which energy is absorbed from the surroundings as heat.

Question 2

A chemical reaction occurs in a beaker and the temperature of the solution increases. Which of the following statements is true about the reaction?

Accepted Answer

The reaction is exothermic because it releases heat to the surroundings.

Question 3

Which equation correctly expresses the first law of thermodynamics for a closed system?

Accepted Answer

$ \Delta E = q + w $

Question 4

A gas in a piston absorbs 150 J of heat and does 40 J of work by expanding. What is the change in internal energy ($ \Delta E $) of the gas?

Accepted Answer

$ \Delta E = 110 \ \mathrm{J} $

Question 5

Which of the following best defines 'system' and 'surroundings' in thermochemistry?

Accepted Answer

The system is the part of the universe we are studying, and the surroundings are everything else.

Question 6

Which of the following is an example of work being done by a system on its surroundings?

Accepted Answer

A gas expands and pushes up a piston.

Question 7

Which equation is used to calculate the heat ($ q $) absorbed or released by a substance when its temperature changes?

Accepted Answer

$ q = m c \Delta T $

Question 8

A 50.0 g sample of water is heated from $ 25.0 ^\circ \mathrm{C} $ to $ 75.0 ^\circ \mathrm{C} $. The specific heat capacity of water is $ 4.18 \ \mathrm{J} / (\mathrm{g} \cdot ^\circ \mathrm{C}) $. How much heat ($ q $) is absorbed by the water?

Accepted Answer

$ 10,450 \ \mathrm{J} $

Question 9

Which of the following statements about temperature and heat is correct?

Accepted Answer

Temperature is a measure of the average kinetic energy of particles, while heat is the energy transferred due to a temperature difference.

Question 10

Which equation describes the pressure-volume work done by a gas during expansion or compression at constant pressure?

Accepted Answer

$ w = -P \Delta V $

Question 11

A balloon is inflated from $ 2.00 \ \mathrm{L} $ to $ 5.00 \ \mathrm{L} $ against a constant external pressure of $ 1.00 \ \mathrm{atm} $. Calculate the work done by the gas. ($ 1 \ \mathrm{L} \cdot \mathrm{atm} = 101.3 \ \mathrm{J} $)

Accepted Answer

$ 303.9 \ \mathrm{J} $

Question 12

Which of the following best describes the concept of specific heat capacity?

Accepted Answer

The amount of heat required to raise the temperature of 1 gram of a substance by $ 1 ^\circ \mathrm{C} $.

Question 13

Which of the following is a correct statement of the law of conservation of energy?

Accepted Answer

Energy cannot be created or destroyed, only converted from one form to another.

Question 14

A metal block at $ 100 ^\circ \mathrm{C} $ is placed in $ 100 \ \mathrm{g} $ of water at $ 25 ^\circ \mathrm{C} $. The final temperature is $ 30 ^\circ \mathrm{C} $. If the specific heat of the metal is $ 0.50 \ \mathrm{J} / (\mathrm{g} \cdot ^\circ \mathrm{C}) $ and the mass of the metal is $ 50 \ \mathrm{g} $, how much heat did the metal lose?

Accepted Answer

$ 1,750 \ \mathrm{J} $

Question 15

Which of the following is NOT a form of energy relevant to thermochemistry?

Accepted Answer

Magnetic monopole energy

Question 16

Which of the following best explains why the direction of heat transfer is determined by temperature difference?

Accepted Answer

Heat always flows from a region of higher temperature to lower temperature.

Question 17

A reaction occurs in a bomb calorimeter (constant volume). Which of the following is true?

Accepted Answer

No work is done because $ \Delta V = 0 $.

Question 18

Which of the following is the correct definition of thermochemistry?

Accepted Answer

The study of the energy changes that accompany chemical reactions.

Question 19

Which of the following equations would you use to determine the heat required to raise the temperature of a substance, given its mass, specific heat, and temperature change?

Accepted Answer

$ q = m c \Delta T $

Question 20

A sample of gas does $ 200 \ \mathrm{J} $ of work on its surroundings and absorbs $ 300 \ \mathrm{J} $ of heat. What is the change in internal energy ($ \Delta E $)?

Accepted Answer

$ 100 \ \mathrm{J} $

Thermochemistry and Energy: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards