Deck 7: Thermodynamic Processes, Thermochemistry, Spontaneous Processes and Thermodynamic Equilibrium

Question 1

Calculate DS°_rxn for the following
NH₃(g) + HCl(g) $\rightarrow$ NH₄Cl(s)

A) 284.5 J·K^-1
B) -284.5 J·K^-1
C) -203.5 J·K^-1
D) 89.1 J·K^-1

Answer 1

-284.5 J·K^-1

Question 2

Calculate DS°_rxn for the following
3NO₂(g) + H₂O(l) $\rightarrow$ 2HNO₃(l) + NO(g)

A) 56.28 J·K^-1
B) -56.28 J·K^-1
C) 268.1 J·K^-1
D) -268.1 J·K^-1

Answer 2

-268.1 J·K^-1

Question 3

pertain to the reaction CCl₄(l) $\rightarrow$ CCl₄(g).

-Refer to Exhibit 13-1. What is the value of DS°_vap?

A) 93.3 J·K^-1
B) -93.3 J·K^-1
C) 32.5 J·K^-1
D) -32.5 J·K^-1
E) None of the above

Answer 3

93.3 J·K^-1

Question 4

Allotropic forms of an element that do not represent an element in its standard state will have

D) S°=0
E) None of the above

Question 5

A solid of mass m initially at T₀ is heated to T₁ at constant pressure where it proceeds to melt. Once all of the solid is in the liquid phase it is further heated to T₂. If the solid and liquid have specific heat capacities of cp^sol and cp^sol respectively, which equation below best represents the change in entropy for this system?


E) B and D

Question 6

The constant that connects the entropy of a system to the number of microstates is

A) R
B)
C) k_B
D)

E) B and C

Question 7

For a reversible isothermal process involving ideal gases

D) b and c
E) all of the above
F) none of the above

Question 8

Copper has a specific heat capacity of 0.0920 cal·K^-1·g^-1 at 298 K. What is the molar heat capacity of copper in J·K^-1·mol^-1?

A) 22.6 J·K^-1·mol^-1
B) 24.5 J·K^-1·mol^-1
C) 1.40 J·K^-1·mol^-1
D) 3.46´10^-4 J·K^-1·mol^-1
E) None of the above

Question 9

A 125.0 g piece of iron is heated to 400°C and placed in 300.0 g of water at 25°C. If the specific heat capacities of iron and water are 0.449 J·K^-1·g^-1 and 4.184 J·K^-1·g^-1 respectively, what will be the final temperature of the water?

A) 32°C
B) 41°C
C) 101°C
D) 383°C
E) None of the above

Question 10

The decomposition of NO and NO₂ to the elements proceeds via the following two reactions. Calculate the enthalpy change for the reaction
2NO(g) + O₂(g) $\rightarrow$ 2NO₂(g)

A) 244 kJ
B) -244 kJ
C) -114 kJ
D) -293 kJ
E) none of the above

Question 11

Sublimation is the process of changing phases directly from a solid to a gas. Calculate DH°_sub for elemental iodine.

A) 62.44 kJ·mol^-1
B) -62.44 kJ·mol^-1
C) 39.98 kJ·mol^-1
D) 19.36 kJ·mol^-1

Question 12

The standard state of carbon as a free element is graphite. C₆₀ is an allotropic form of carbon belonging to a class of structures known as fullerenes. for C₆₀ should be

A) zero
B) positive
C) negative
D) equal to
for the other allotropic forms of carbon
E) A and D