Q: Given the following mechanism: NO(g) + NO(g) \rightleftharpoons N_2O_2(g) (fast, equilibrium) N_2O_2(g) + $$H_2(g$$) \rightarrow H_2O(g) + N_2O(g) (slow) N_2O(g) + $$H_2(g$$) \rightarrow $$N_2(g) + H_2O(g) ($$fast) What is the correct rate law for the overall reaction?

$$\text{Rate} = k[NO]^2[H_2$]$$

Q: For the elementary reaction $$A + 2B \rightarrow 2C + D$$, what is the molecularity and rate law?

$$\text{Rate} = k[A][B]^2$$, termolecular

Q: For the galvanic cell $$\text{Ag}(s) | \text{Ag}^+(aq) || \text{Cu}^{2+}(aq) | \text{Cu}(s)$$, what reaction occurs at the cathode?

$$\text{Ag}^+(aq) + e^- \rightarrow \text{Ag}(s)$$

Q: Which of the following is the correct standard cell notation for $$2\text{H}^+(aq) + 2\text{Ag}(s) \rightarrow \text{H}_2(g) + 2\text{Ag}^+(aq)$$?

$$\text{Ag}(s) | \text{Ag}^+(aq) || \text{H}^+(aq) | \text{H}_2(g)$$

Question 1

A reaction has a two-step mechanism, with the first step being endothermic and the second step having the highest activation energy. Which statement about the reaction is FALSE?

Accepted Answer

The second step has the lowest activation energy.

Question 2

Given the following mechanism:
NO(g) + NO(g) \rightleftharpoons N_2O_2(g) (fast, equilibrium)
N_2O_2(g) + $$H_2(g$$) \rightarrow H_2O(g) + N_2O(g) (slow)
N_2O(g) + $$H_2(g$$) \rightarrow $$N_2(g) + H_2O(g) ($$fast)
What is the correct rate law for the overall reaction?

Accepted Answer

$$	ext{Rate} = k[NO]^2[H_2$]$$

Question 3

For the reaction $$4	ext{CH}_3	ext{I}(aq) + 	ext{NH}_3(aq) ightarrow (	ext{CH}_3)_4	ext{NI}(aq) + 3	ext{HI}(aq)$$, if the rate of change of $$[	ext{HI}] at 5.0 $$minutes is $$3.0\ 	ext{M/min}$$, what is the rate of change of $$[	ext{CH}_3	ext{I}] at $$the same time?

Accepted Answer

$$-0.30\ 	ext{M/min}$$

Question 4

The reaction $$2A(aq) + 2B(aq) \rightarrow 4C(g) + 5D(aq) is $$first order in A and second order in B. What is the overall reaction order?

Accepted Answer

3

Question 5

Which of the following statements about reaction rates is TRUE?
I. The rate increases when activation energy increases
II. The rate increases when activation energy decreases
III. The rate increases when temperature increases
IV. The rate increases when temperature decreases

Accepted Answer

II and III

Question 6

A catalyst is added to a reaction at constant temperature. Which of the following is changed by the catalyst?

Accepted Answer

Activation Energy, Rate Constant(s), and Rate

Question 7

The rate law for $$2	ext{NO}(g) + 	ext{O}_2(g) ightarrow 2	ext{NO}_2(g) is$$ $$	ext{rate} = k[NO]^2[O_2$]. $$Which mechanism is consistent with this rate law?

Accepted Answer

I only

Question 8

For the reaction $$2	ext{ICl}(g) + 	ext{H}_2(g) ightarrow 	ext{I}_2(g) + 2	ext{HCl}(g)$$, the rate law is $$	ext{rate} = k[	ext{ICl}][	ext{H}_2]. $$What are the units of the rate constant $$k$$?

Accepted Answer

$$	ext{M}^{-1}	ext{s}^{-1}$$

Question 9

For the reaction $$2A(g) + B(g) ightarrow C(g)$$, the rate law is $$	ext{rate} = k[A]^3. If$$ $$[A] is $$tripled, how does the reaction rate change?

Accepted Answer

The rate is 27 times the original rate.

Question 10

In the mechanism for ozone degradation:
ClO(g) + BrO(g) \rightarrow Cl(g) + Br(g) + $$O_2(g)
Cl(g$$) + $$O_3(g$$) \rightarrow ClO(g) + $$O_2(g)
Br(g$$) + $$O_3(g$$) \rightarrow BrO(g) + $$O_2(g)
$$Which are the catalysts and intermediates?

Accepted Answer

Catalysts: Cl, Br; Intermediates: ClO, BrO

Question 11

For the elementary reaction $$A + 2B \rightarrow 2C + D$$, what is the molecularity and rate law?

Accepted Answer

$$	ext{Rate} = k[A][B]^2$$, termolecular

Question 12

What is the oxidation number of sulfur in potassium bisulfate ($$	ext{KHSO}_4$$)?

Accepted Answer

+6

Question 13

Which statement about oxidation is NOT true?

Accepted Answer

Substances that are oxidized decrease in oxidation state.

Question 14

In the unbalanced reaction $$	ext{MnO}_4^- (aq) + 	ext{SO}_3$$^{2-}$$ (aq) ightarrow 	ext{MnO}_2 (aq) + 	ext{SO}_4$$^{2-}$$ (aq)$$, which species is the reducing agent?

Accepted Answer

SO$$_3$$^{2-}$$

Question 15

For the galvanic cell $$	ext{Ag}(s) | 	ext{Ag}^+(aq) || 	ext{Cu}^{2+}(aq) | 	ext{Cu}(s)$$, what reaction occurs at the cathode?

Accepted Answer

$$	ext{Ag}^+(aq) + e^- ightarrow 	ext{Ag}(s)$$

Question 16

A molten mixture contains NaCl and NaBr. The standard reduction potentials are:
Cl$$_2(g) + 2e$^-$$ $$\rightarrow 2Cl$^- (E$^\circ = +1.358 V)
Br$_2(g) + 2e$^-$$ $$\rightarrow 2Br$^- (E$^\circ = +1.0873 V)
$$Which species is oxidized at the anode during electrolysis?

Accepted Answer

Cl$$^-$$

Question 17

One cell of a lead storage battery produces a voltage of 2.09 V and lead is oxidized from 0 to +2. Calculate the maximum free energy in kJ that can be obtained in a single cell under standard conditions. $$\Delta G^\circ = -nFE_{cell}^\circ$$

Accepted Answer

$$-40.3\ 	ext{kJ}$$

Question 18

In a galvanic cell, K$$^+$$ ions from the salt bridge migrate toward the cathode. What is the most accurate explanation for this migration?

Accepted Answer

The cathode solution becomes increasingly negative as the reaction proceeds.

Question 19

Which of the following is the correct standard cell notation for $$2	ext{H}^+(aq) + 2	ext{Ag}(s) ightarrow 	ext{H}_2(g) + 2	ext{Ag}^+(aq)$$?

Accepted Answer

$$	ext{Ag}(s) | 	ext{Ag}^+(aq) || 	ext{H}^+(aq) | 	ext{H}_2(g)$$

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