Chemical Theromodynamics: Quiz

Question 1

Which of the following exhibits a negative entropy change?

An ice cube melts on the table
Fast moving vehicles halt and line up during red light
Students running around the field during break time
A lump of sugar dissolves in a glass of water

Answer 1

Fast moving vehicles halt and line up during red light

Question 2

Which best describes a spontaneous process?

It is instantaneous
It releases heat
It can proceed on its own
It has positive entropy change

Answer 2

It can proceed on its own

Question 3

What happens to the entropy of the given reaction below?

CO2(g) —> CO2(s)

Increases
Remains the same
Decreases
Significantly increase then becomes zero

Answer 3

Decreases

(g) gas turned into (s) solid

Question 4

The entropy of a substance is a measure of its ____.

Disorder
Order
Energy
Temperature

Answer 4

Disorder

Question 5

According to the third law of thermodynamics, at what temperature will entropy become zero?

25oC
273.15 K
100oC
0 K

Answer 5

0 K

Question 6

Which of the following is a non-spontaneous process?

Rain falls from the sky
A plant grows into tree
A cellphone battery is being recharged
A fruit rot after several days

Answer 6

A cellphone battery is being recharged

Question 7

Which of the following has the greatest entropy?

I. H2O(S)

II. H2O(l)

III. H2O(g)

I and III only
I and II only
I, II, and III
III only

Answer 7

III only

Only III. is in a gaseous state

Question 8

Identify the type of process under chemical thermodynamics involved in the situation below:

“Vapor is converted to solid (Water vapor to ice)”

Spontaneous
Natural
Undetermined
Non-spontaneous

Answer 8

Non-Spontaneous

Question 9

Identify the type of process under chemical thermodynamics involved in the situation below:

“Vapor is converted to solid (Water vapor to ice)”

Spontaneous
Natural
Undetermined
Non-spontaneous

Answer 9

Non-spontaneous

Question 10

Which law states that entropy is always increasing?
First Law of Thermodynamics
Second Law of Thermodynamics
Third Law of Thermodynamics
Gibbs Law

Answer 10

Second Law of Thermodynamics

Question 11

Which phase of matter has the greatest motion and least orderly arrangement?
Gas
Solid and gas
Solid
Liquid

Answer 11

Gas

Question 12

Which system has the greatest entropy of formation?
H2O(s) at 298 K
H2O(l) at 298 K
H2O(g) at 298 K

Answer 12

H2O(g) at 298 K

Gas has ta highest disorder

Question 13

A chemical reaction will always be spontaneous (thermodynamically favored) under which conditions?
Endothermic with a decrease in entropy
Exothermic with an increase in entropy
Exothermic with a decrease in entropy
Endothermic with an increase in entropy

Answer 13

Exothermic with an increase in entropy

Question 14

Which phase of matter has the least motion and greatest orderly arrangement?
Liquid
Gas
Solid
Liquid and solid

Answer 14

Solid

Question 15

The entropy of a substance is a measure of its
Work capacity
Disorder
Free energy
Temperature

Answer 15

Disorder

Question 16

Gibbs free energy change is expressed as ___________.
ΔG° = ΔH° + TΔS°
ΔG° = ΔH° - TΔS°
ΔG° = ΔS° + TΔH°
ΔG° = ΔS° - TΔH°

Answer 16

ΔG° = ΔH° - TΔS°

Question 17

Predict whether the entropy will increase or decrease in the given reaction.

Choose the best explanation that supports your prediction.

N2H4(l) → N2(g) + 2 H2(g)

Decreases, because there are more product particles than reactant particles
Increases, since the reaction goes from a liquid to a 3-moles of gases
Decreases, since the reaction goes from liquid to gas
Increases, since the reaction goes from liquid to gas

Answer 17

Increases, since the reaction goes from a liquid to a 3-moles of gases