Entropy and Applications of Thermodynamics Quiz

Entropy increases when matter and/or energy becomes more dispersed or spread out. Which of the following is an example of this?

• A) A gas being compressed into a smaller volume

• B) Ice melting into water

• C) Water freezing into ice

• D) A solid being cut into smaller pieces

What happens to entropy when a substance changes phase from solid to liquid, or from liquid to gas?

• A) Entropy decreases

• B) Entropy remains constant

• C) Entropy increases

• D) Entropy is not affected by phase changes

When a gas expands into a larger volume at constant temperature, what happens to the entropy of the system?

• A) The entropy decreases

• B) The entropy increases

• C) The entropy remains unchanged

• D) The entropy fluctuates unpredictably

According to the Maxwell-Boltzmann Distribution, what effect does increasing the temperature have on the distribution of kinetic energies of the gas particles?

• A) It narrows the distribution

• B) It does not change the distribution

• C) It broadens the distribution

• D) It shifts the distribution to lower energies

What is the relationship between temperature and entropy of a system according to the provided material?

• A) As temperature decreases, entropy decreases

• B) As temperature increases, entropy decreases

• C) As temperature increases, entropy increases

• D) Temperature and entropy are not related

What is the standard entropy change, ΔS°, for the reaction 2 O₃(g) → 3 O₂(g)?

• 137.4 J/mol-K

• -427.5 J/mol-K

• -198.3 J/mol-K

• 186.4 J/mol-K

According to the table of molar entropies, what is the entropy value for NH₃(g)?

• 192.5 J/mol-K

• 238.8 J/mol-K

• 205.0 J/mol-K

• 130.6 J/mol-K

For the reaction N₂(g) + 3 H₂(g) → 2 NH₃(g), the entropy change prediction is:

• Positive, because more moles of gas are formed.

• Negative, because less moles of gas are formed and less freely moving particles.

• Positive, because changing from a liquid to a gas.

• Negative, because making a solid, fewer particles freely moving.

What is the entropy value of O₂(g) as given in the table of molar entropies?

• 188.8 J/mol-K

• 205.0 J/mol-K

• 130.6 J/mol-K

• 223.0 J/mol-K

Which substance has the lowest entropy value according to the table of molar entropies?

• Na(s)

• H₂O(l)

• NH₃(g)

• Cl₂(g)