Question 1

For the hypothetical reaction A + 3B $\rarr$ 2C, the rate of appearance of C given by ($\Delta$[C]/$\Delta$t) may also be expressed as

Accepted Answer

A) ($\Delta$[C]/$\Delta$t) = $\Delta$[A]/$\Delta$t 
B) ($\Delta$[C]/$\Delta$t) = -(3/2) $\Delta$[B]/$\Delta$t 
C) ($\Delta$[C]/$\Delta$t) = -(2/3) $\Delta$[B]/$\Delta$t 
D) ($\Delta$[C]/$\Delta$t) = -(1/2) $\Delta$[A]/$\Delta$t 
A) ($\Delta$[C]/$\Delta$t) = $\Delta$[A]/$\Delta$t 
B) ($\Delta$[C]/$\Delta$t) = -(3/2) $\Delta$[B]/$\Delta$t 
C) ($\Delta$[C]/$\Delta$t) = -(2/3) $\Delta$[B]/$\Delta$t 
D) ($\Delta$[C]/$\Delta$t) = -(1/2) $\Delta$[A]/$\Delta$t

Question 2

When the concentrations of reactant molecules are increased, the rate of reaction increases. The best explanation for this phenomenon is that as the reactant concentration increases,

Accepted Answer

A)  the average kinetic energy of molecules increases. 
B)  the frequency of molecular collisions increases. 
C)  the rate constant increases. 
D)  the activation energy increases. 
E)  the order of reaction increases. 
A)  the average kinetic energy of molecules increases. 
B)  the frequency of molecular collisions increases. 
C)  the rate constant increases. 
D)  the activation energy increases. 
E)  the order of reaction increases.

Question 3

Concerning the rate law, Rate = k[A]0, what are appropriate units for the rate constant k

Accepted Answer

A)  s-1 
B)  M-1s-1 
C)  M-2s-1 
D)  M/s 
E)  M2/s 
A)  s-1 
B)  M-1s-1 
C)  M-2s-1 
D)  M/s 
E)  M2/s

Question 4

A reaction is experimentally found to follow the rate law, Rate = k[A]2 where k = 0.355 M-1min-1. Starting with [A]o = 1.55 M, how many seconds will it take for [A]t = 0.150M

Accepted Answer

A)  6.58 s 
B)  395 s 
C)  6.02 s 
D)  17.0 s 
E)  1.02 x 103 s 
A)  6.58 s 
B)  395 s 
C)  6.02 s 
D)  17.0 s 
E)  1.02 x 103 s

Question 5

The thermal decomposition of acetaldehyde, CH3CHO $\rarr$ CH4 + CO, is a second-order reaction. The following data were obtained at 518$\circ$C. $\begin{array}{cc}
\text { Time, } \mathrm{s} & \text { Pressure } \mathrm{CH}_{3} \mathrm{CHO}, \mathrm{mmHg} \\hline
0 & 364 \
42 & 330 \
105 & 290 \
720 & 132
\end{array}$ Calculate the rate constant for the decomposition of acetaldehyde from the above data.

Accepted Answer

A)  2.2 * 10-3/s 
B)  0.70 mmHg/s 
C)  2.2 * 10-3/mmHg·s 
D)  6.7 *10-6/mmHg·s 
E)  5.2 * 10-5/mmHg·s 
A)  2.2 * 10-3/s 
B)  0.70 mmHg/s 
C)  2.2 * 10-3/mmHg·s 
D)  6.7 *10-6/mmHg·s 
E)  5.2 * 10-5/mmHg·s

Question 6

B is a catalyst in the following mechanism: $\begin{array}{lr}
\mathrm{A} \rightarrow \mathrm{C}+\mathrm{B} & \text { slow } \
\mathrm{A}+\mathrm{B} \rightarrow \mathrm{C}+\mathrm{E} & \text { fast }
\end{array}$

Accepted Answer

A) True 
 B)False

Question 7

At 25$\circ$C, the second-order reaction NOCl(g) $\rarr$ NO(g) + 1/2Cl2(g)is 50% complete after 5.82 hours when the initial concentration of NOCl is 4.46 mol/L. How long will it take for the reaction to be 75% complete

Accepted Answer

A)  8.22 hr 
B)  11.6 hr 
C)  15.5 hr 
D)  17.5 hr 
E)  23.0 hr 
A)  8.22 hr 
B)  11.6 hr 
C)  15.5 hr 
D)  17.5 hr 
E)  23.0 hr

Question 8

The reaction 2A + B $\rarr$ products is second order with respect to A and zero-order with respect toB. Starting with 0.135 M of A, what is the concentration of A after 35 min if the rate constant is 0.11 M-1s-1

Accepted Answer

A)  4.0 x 10-3 M 
B)  4.2 x 10-3 M 
C)  4.4 x 10-3 M 
D)  4.6 x 10-3 M 
A)  4.0 x 10-3 M 
B)  4.2 x 10-3 M 
C)  4.4 x 10-3 M 
D)  4.6 x 10-3 M

Question 9

Use the table of data shown below to calculate the average rate of the reaction A$\rarr$B between 10 s and 20 s. $\begin{array}{cl}
\text { time }(\mathrm{s}) & {[\mathrm{A}] \mathrm{mol} / \mathrm{L}} \
0 & 0.20 \
5 & 0.14 \
10 & 0.10 \
15 & 0.071 \
20 & 0.050
\end{array}$

Accepted Answer

A)  2 * 10-3 M/s 
B)  4 * 10-3 M/s 
C)  6 * 10-3 M/s 
D)  8 * 10-3 M/s 
E)  none of the above 
A)  2 * 10-3 M/s 
B)  4 * 10-3 M/s 
C)  6 * 10-3 M/s 
D)  8 * 10-3 M/s 
E)  none of the above

Question 10

Nitric acid is formed by the gas-phase hydrolysis of N2O5. The energy profile curve for the reaction N2O5 + H2O $\rarr$2HNO3 is shown here. The reaction is endothermic and the activation energy of the reverse reaction is larger than for the forward reaction.

Accepted Answer

A) True 
 B)False

Question 11

The activation energy of a certain uncatalyzed reaction is 64 kJ/mol. In the presence of a catalyst, the Ea is 55 kJ/mol. How many times faster is the catalyzed than the uncatalyzed reaction at 400$\circ$C Assume that the frequency factor remains the same.

Accepted Answer

A)  5.0 times 
B)  1.16 times 
C)  15 times 
D)  2.0 times 
E)  0.2 times 
A)  5.0 times 
B)  1.16 times 
C)  15 times 
D)  2.0 times 
E)  0.2 times

For the hypothetical reaction A + 3B $\rarr$ 2C, the rate of appearance of C given by ( $\Delta$ [C]/ $\Delta$ t) may also be expressed as

When the concentrations of reactant molecules are increased, the rate of reaction increases. The best explanation for this phenomenon is that as the reactant concentration increases,

Concerning the rate law, Rate = k[A]⁰, what are appropriate units for the rate constant k

A reaction is experimentally found to follow the rate law, Rate = k[A]² where k = 0.355 M^-1min^-1. Starting with [A]_o = 1.55 M, how many seconds will it take for [A]_t = 0.150M

The thermal decomposition of acetaldehyde, CH₃CHO $\rarr$ CH₄ + CO, is a second-order reaction. The following data were obtained at 518^$\circ$C. Time, Pressure , 0 364 42 330 105 290 720 132 Calculate the rate constant for the decomposition of acetaldehyde from the above data.

B is a catalyst in the following mechanism: \rightarrow+ slow +\rightarrow+ fast

At 25^$\circ$C, the second-order reaction NOCl(g) $\rarr$ NO(g) + ¹/₂Cl₂(g)is 50% complete after 5.82 hours when the initial concentration of NOCl is 4.46 mol/L. How long will it take for the reaction to be 75% complete

The reaction 2A + B $\rarr$ products is second order with respect to A and zero-order with respect toB. Starting with 0.135 M of A, what is the concentration of A after 35 min if the rate constant is 0.11 M^-1s^-1

Use the table of data shown below to calculate the average rate of the reaction A $\rarr$ B between 10 s and 20 s. time () []/ 0 0.20 5 0.14 10 0.10 15 0.071 20 0.050

The activation energy of a certain uncatalyzed reaction is 64 kJ/mol. In the presence of a catalyst, the E_a is 55 kJ/mol. How many times faster is the catalyzed than the uncatalyzed reaction at 400^$\circ$C Assume that the frequency factor remains the same.

Chemistry: The Study of Change

Atoms Molecules and Ions

Mass Relationships in Chemical Reactions

Reactions in Aqueous Solutions

Gases

Thermochemistry

Quantum Theory and the Electronic Structure of Atoms

Periodic Relationships Among the Elements

Chemical Bonding I: Basic Concepts

Chemical Bonding II: Molecular Geometry and Hybridization of Atomic

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Entropy Free Energy and Equilibrium

Electrochemistry

Nuclear Chemistry

Chemistry in the Atmosphere

Metallurgy and the Chemistry of Metals

Nonmetallic Elements and Their Compounds

Transition Metals Chemistry and Coordination Compounds

Organic Chemistry

Synthetic and Natural Organic Polymers

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Exam 13: Chemical Kinetics

For the hypothetical reaction A + 3B →\rarr→ 2C, the rate of appearance of C given by ( Δ\DeltaΔ [C]/ Δ\DeltaΔ t) may also be expressed as

When the concentrations of reactant molecules are increased, the rate of reaction increases. The best explanation for this phenomenon is that as the reactant concentration increases,

Concerning the rate law, Rate = k[A]0, what are appropriate units for the rate constant k

A reaction is experimentally found to follow the rate law, Rate = k[A]2 where k = 0.355 M-1min-1. Starting with [A]o = 1.55 M, how many seconds will it take for [A]t = 0.150M

The thermal decomposition of acetaldehyde, CH3CHO →\rarr→ CH4 + CO, is a second-order reaction. The following data were obtained at 518 ∘\circ∘ C. Time, Pressure , 0 364 42 330 105 290 720 132 Calculate the rate constant for the decomposition of acetaldehyde from the above data.

B is a catalyst in the following mechanism: \rightarrow+ slow +\rightarrow+ fast

At 25 ∘\circ∘ C, the second-order reaction NOCl(g) →\rarr→ NO(g) + 1/2Cl2(g)is 50% complete after 5.82 hours when the initial concentration of NOCl is 4.46 mol/L. How long will it take for the reaction to be 75% complete

The reaction 2A + B →\rarr→ products is second order with respect to A and zero-order with respect toB. Starting with 0.135 M of A, what is the concentration of A after 35 min if the rate constant is 0.11 M-1s-1

Use the table of data shown below to calculate the average rate of the reaction A →\rarr→ B between 10 s and 20 s. time () []/ 0 0.20 5 0.14 10 0.10 15 0.071 20 0.050

Nitric acid is formed by the gas-phase hydrolysis of N2O5. The energy profile curve for the reaction N2O5 + H2O →\rarr→ 2HNO3 is shown here. The reaction is endothermic and the activation energy of the reverse reaction is larger than for the forward reaction.

The activation energy of a certain uncatalyzed reaction is 64 kJ/mol. In the presence of a catalyst, the Ea is 55 kJ/mol. How many times faster is the catalyzed than the uncatalyzed reaction at 400 ∘\circ∘ C Assume that the frequency factor remains the same.

Chemistry: The Study of Change

Atoms Molecules and Ions

Mass Relationships in Chemical Reactions

Reactions in Aqueous Solutions

Gases

Thermochemistry

Quantum Theory and the Electronic Structure of Atoms

Periodic Relationships Among the Elements

Chemical Bonding I: Basic Concepts

Chemical Bonding II: Molecular Geometry and Hybridization of Atomic

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Entropy Free Energy and Equilibrium

Electrochemistry

Nuclear Chemistry

Chemistry in the Atmosphere

Metallurgy and the Chemistry of Metals

Nonmetallic Elements and Their Compounds

Transition Metals Chemistry and Coordination Compounds

Organic Chemistry

Synthetic and Natural Organic Polymers

Filters

For the hypothetical reaction A + 3B $\rarr$ 2C, the rate of appearance of C given by ( $\Delta$ [C]/ $\Delta$ t) may also be expressed as

Concerning the rate law, Rate = k[A]⁰, what are appropriate units for the rate constant k

A reaction is experimentally found to follow the rate law, Rate = k[A]² where k = 0.355 M^-1min^-1. Starting with [A]_o = 1.55 M, how many seconds will it take for [A]_t = 0.150M

The thermal decomposition of acetaldehyde, CH₃CHO $\rarr$ CH₄ + CO, is a second-order reaction. The following data were obtained at 518^$\circ$C. Time, Pressure , 0 364 42 330 105 290 720 132 Calculate the rate constant for the decomposition of acetaldehyde from the above data.

At 25^$\circ$C, the second-order reaction NOCl(g) $\rarr$ NO(g) + ¹/₂Cl₂(g)is 50% complete after 5.82 hours when the initial concentration of NOCl is 4.46 mol/L. How long will it take for the reaction to be 75% complete

The reaction 2A + B $\rarr$ products is second order with respect to A and zero-order with respect toB. Starting with 0.135 M of A, what is the concentration of A after 35 min if the rate constant is 0.11 M^-1s^-1

Use the table of data shown below to calculate the average rate of the reaction A $\rarr$ B between 10 s and 20 s. time () []/ 0 0.20 5 0.14 10 0.10 15 0.071 20 0.050

The activation energy of a certain uncatalyzed reaction is 64 kJ/mol. In the presence of a catalyst, the E_a is 55 kJ/mol. How many times faster is the catalyzed than the uncatalyzed reaction at 400^$\circ$C Assume that the frequency factor remains the same.