Name:    Practice Final B

Multiple Choice
Identify the choice that best completes the statement or answers the question.

1.

For bromine, H° vap = 30.91 kJ/mol and S° vap = 93.23 J/Kmol.   What is the normal boiling point for bromine?
 A) 332°C B) 124°C C) 25°C D) 58°C

2.

The formation constant (Kf) for the reaction shown below is 1.7x107 at 25 °C.  What is G° at this temperature? A) –41.2 kJ B) –17.9 kJ C) –1.5 kJ D) –3.5 kJ

3.

For a particular process G is less than H.  Therefore
 A) S is zero B) S is positive C) S is negative D) S is positive if H is negative and S is negative if H is positive

4.

Elemental boron can be formed by the reaction of boron trichloride and hydrogen, as shown below.  If S° for this reaction is 80.3 J/K, what is S° for BCl3(g)?

 BCl3(g)        +       1.5 H2(g) B(s)         +   3 HCl(g) S° (J/Kmol) ??? 130.6 5.87 186.8
 A) 18.2 J/Kmol B) 290.1 J/Kmol C) 450.6 J/Kmol D) –18.2 J/Kmol

5.

Doubling all the coefficients in the equation for a cell reaction
 A) does not change E° or G° B) doubles both E° and G° C) doubles E°, but does not change G° D) doubles G°, but does not change E°

6.

Calculate G° for a cell that utilizes oxidation of copper by nitric acid at 25 °C.

Cu2+(aq) + 2 e Cu(s)                              E° = 0.34 V
NO3(aq) + 4 H+(aq) + 3 e NO(g) + 2 H2O(l)         E° = 0.96 V
 A) –360 kJ B) –120 kJ C) –240 kJ D) –180 kJ

7.

Which of the following substances is the strongest oxidizing agent? A) Cr2+ B) Co2+ C) Fe2+ D) Sr2+

8.

Predict the sign of S° for the following reaction:

K2SO4 (s) 2 K+ (aq) + SO42– (aq)
 A) S° > 0 B) S° = 0 C) S° < 0 D) More information is needed to make a reasonable prediction

9.

Which of the following substances will reduce Ag+ but not Cu2+?
 A) Br2 B) Sn2+ C) Fe3+ D) I2

10.

Which of the following substances is the strongest reducing agent? A) Pb(s) B) Pt(s) C) Br–(aq) D) Ca(s)

11.

In an electrochemical cell, Q= 0.0010 and K=0.10.  Which statement below is true?
 A) Ecell is negative and E°cell is positive B) Ecell is positive and E°cell is negative C) Both Ecell and E°cell are positive D) Both Ecell and E°cell are negative

12.

A redox reaction employed in an elelctrochemical cell has a negative DG°rxnWhich statement is true?
 A) E°cell is positive; K <1 B) E°cell is negative; K <1 C) E°cell is positive; K >1 D) E°cell is negative; K >1