Chapter 5 Quiz

Question 1

System

Answer 1

Part of the universe being studied​

Question 2

Surroundings​

Answer 2

Rest of the universe that interacts with the system​

Question 3

First Law of Thermodynamics ​

Answer 3

-Law of conservation of energy​

-Energy can be neither created or destroyed in an isolated system​

Question 4

Enthalpy​

Answer 4

sum of the total energy of the system and the work done ​

Question 5

exothermic reaction​

Answer 5

When ΔH is negative, heat is released by the system​ (ex: Hand warmers)

Question 6

endothermic reaction​

Answer 6

When ΔH is positive, heat is absorbed by the system​ (ex: freezer packs)

Question 7

Heat Capacity

Answer 7

the amount of energy required to raise the temperature of a substance by 1 K (1 *C).​

Question 8

Specific heat capacity

Answer 8

( specific heat)- the amount of energy required to raise the temperature of 1 g of a substance by 1 K (or 1 *C).​

Question 9

State Function

Answer 9

-Function to define the system for only its current state, not the path on how it arrived to that state.​
- It depends only on the present state of the system, not on the path by which the system arrived at that state.

Example= (triangle) H (Enthalpy) is a state function, the total enthalpy change depends only on the initial state (reactants) and the final state (products) of the reaction.​​

Question 10

Hess’s Law​

Answer 10

Hess’s law: If a reaction is carried out in a series of steps, (triangle) H for the overall reaction will be equal to the sum of the enthalpy changes for the individual steps.​

Question 11

In thermodynamics, work is defined as

Answer 11

c) Force applied over a distance W=P/\V

Question 12

What is the SI unit of energy?

Answer 12

b) Joule

Question 13

Which of the following is true for an exothermic reaction?

Answer 13

c) ΔH is negative

Question 14

What is the term for the amount of heat required to raise the temperature of 1 gram of
a substance by 1°C?

Answer 14

b) Specific heat capacity

Question 15

A system absorbs 100 J of heat and performs 40 J of work. What is its change in
internal energy?

Answer 15

a) 60 J

Question 16

9. If a system releases 200 J of heat and does 50 J of work on the surroundings, what is
   the change in internal energy (ΔE)?

Answer 16

a) -250 J

Question 17

If a system absorbs 500 J of heat and performs 200 J of work, what is the change in internal energy (ΔE)?

Answer 17

b) +300 J

Question 18

The enthalpy change (ΔH) for an

Answer 18

c) Negative

Question 19

In an open system, which of the following can be exchanged with the surroundings?

Answer 19

c) Both matter and energy

Question 20

A closed system allows the exchange of

Answer 20

a) Only heat and work

Question 21

Which of the following is an example of an isolated system?

Answer 21

b) A sealed thermos bottle

Question 22

Which of the following best describes an open system?

Answer 22

b) A boiling pot of water without a lid

Question 23

In a closed system, which of the following is true?

Answer 23

b) The system cannot exchange matter with the surroundings.

Question 24

In an endothermic reaction:

Answer 24

b) Heat is absorbed by the system

Question 25

18. Which of the following has the highest specific heat capacity?

Answer 25

b) Water

Question 26

19. In an isobaric process, which of the following remains constant?

Answer 26

c) Pressure

Question 27

Which thermodynamic process occurs at constant temperature?

Answer 27

b) Isothermal

Question 28

What is the difference between enthalpy (ΔH) and internal energy (ΔE) in thermodynamics?

Answer 28

Internal Energy focuses on the energy inside the system. Enthalpy focuses on the energy inside the system plus the work done to volume changes at constant pressure.