Question 1

Which of the following best describes a spontaneous process in thermodynamics?

Accepted Answer

A process that proceeds on its own without continuous external influence.

Question 2

Refer to the image showing solid, liquid, and gas phases. Which phase has the highest entropy?

Accepted Answer

Gas

Question 3

The equation $$\Delta S = k_B \ln W is $$engraved above a statue. What does $$W$$ represent in this equation?

Accepted Answer

The number of ways to arrange the particles in the system

Question 4

For the reversible isothermal expansion of an ideal gas, which equation gives the maximum work done by the system?

Accepted Answer

$$w_{rev} = -nRT \ln \frac{V_f}{V_i}$$

Question 5

Which of the following statements about entropy is correct?

Accepted Answer

Entropy increases as the number of possible arrangements increases.

Question 6

A process is spontaneous at all temperatures if:

Accepted Answer

$$\Delta H  0$$

Question 7

Which equation relates the change in entropy to heat for a reversible process?

Accepted Answer

$$\Delta S = \frac{q_{rev}}{T}$$

Question 8

For the reaction $$N_2O_4 (g) \rightarrow 2 NO_2$ (g)$$, what is the sign of $$\Delta S^o$$?

Accepted Answer

$$\Delta S^o \u003e 0$$

Question 9

Which of the following molecules will have the highest standard molar entropy ($$S^o) at 25$$°C?

Accepted Answer

C$$_3H$_8(g)$$

Question 10

The second law of thermodynamics states that:

Accepted Answer

The entropy of the universe increases for a spontaneous process.

Question 11

If $$\Delta G^o$$ for a reaction is positive, what can be said about the equilibrium constant $$K$$?

Accepted Answer

$$K \u003c 1$$

Question 12

Which equation relates the equilibrium constant $$K to $$the standard free energy change $$\Delta G^o$$?

Accepted Answer

$$\Delta G^o = -RT \ln K$$

Question 13

A reaction has $$\Delta H^o = -297 kJ $$and $$K_P at 25$$°C = $$4.2 	imes 10$$^{20}$$. What happens to K_P$ if the temperature is increased?

Accepted Answer

$$K_P$$ decreases

Question 14

For the transformation of 1.50 mol of A from liquid to gas at constant pressure and 205°C, which equation would you use to calculate $$\Delta S_{sys}$$ for the phase change?

Accepted Answer

$$\Delta S = n \Delta H_{vap} / T$$

Question 15

Which of the following is true for a perfect crystal at 0 K according to the third law of thermodynamics?

Accepted Answer

Entropy is zero.

Question 16

For a reaction at nonstandard conditions, which equation should be used to calculate $$\Delta G$$?

Accepted Answer

$$\Delta G = \Delta G^o + RT \ln Q$$

Question 17

Which process yields the maximum amount of work from a system?

Accepted Answer

Reversible process

Question 18

If a reaction is observed to occur at room temperature and the beaker feels cold, what are the signs of $$\Delta H$$ and $$\Delta S$$?

Accepted Answer

$$\Delta S \u003e 0$$, $$\Delta H \u003e 0$$

Question 19

Which of the following best explains why the most probable state is observed as the number of particles increases (see the probability distribution graph)?

Accepted Answer

The number of possible arrangements for the most probable state increases rapidly with particle number.

Chapter 19: Free Energy and Thermodynamics – Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard