Question 1

Given the following data for the reaction A $\rightarrow$ B, determine the frequency factor, A, of the reaction. $$\begin{array} { c c } 
\boldsymbol { k } ( \boldsymbol { M } / \mathrm { s } ) & \boldsymbol { T } ( \mathbf { K } ) \
2.04 \times 10 ^ { - 4 } & 250 \
6.78 \times 10 ^ { - 3 } & 400
\end{array}$$

Accepted Answer

The frequency factor, A, can be determined using the Arrhenius equation: $ k = A e^{-E_a/RT} $. By taking the natural logarithm of both sides, we get $ \ln k = \ln A - \frac{E_a}{R} \frac{1}{T} $. Using the given data, we can set up two equations and solve for A. The correct calculation yields A ≈ 2.3.

Question 2

Given the following data for the reaction A $\rightarrow$ B, determine the frequency factor, A, of the reaction. $$\begin{array} { c c } 
\boldsymbol { k } ( \boldsymbol { M } / \mathbf { s } ) & \boldsymbol { T } ( \mathbf { K } ) \
0.681 & 500 \
0.715 & 1,000
\end{array}$$

Accepted Answer

The answer of Given the following data for the reaction...

Question 3

Given the following data for the reaction A $\rightarrow$ B, determine the activation energy, E_a, of the reaction. $$\begin{array} { c c } \boldsymbol { k } ( \boldsymbol { M } / \mathrm { s } ) & \boldsymbol { T } ( \mathbf { K } ) \ 0.730 & 250 \ 0.739 & 450 \end{array}$$

Accepted Answer

The answer of Given the following data for the reaction...

Question 4

Given the following data for the reaction A $\rightarrow$ B, determine the frequency factor, A, of the reaction. $$\begin{array} { c c } 
\boldsymbol { k } ( \boldsymbol { M } / \mathrm { s } ) & \boldsymbol { T } \left( { } ^ { \circ } \mathbf { C } \right) \
0.282 & 277 \
0.291 & 627
\end{array}$$

Accepted Answer

The answer of Given the following data for the reaction...

Question 5

Given the following data for the reaction A $\rightarrow$ B, determine the activation energy, E_a, of the reaction. $$\begin{array} { c c } k ( M / s ) & T ( \mathbf { K } ) \ 2.04 \times 10 ^ { - 4 } & 250 \ 6.78 \times 10 ^ { - 3 } & 400 \end{array}$$

Accepted Answer

The Arrhenius equation is:$$k = Ae^{-Ea/RT}$$where:* k is the rate constant* A is the pre-exponential factor* Ea is the activation energy* R is the gas constant* T is the temperatureWe can take the natural logarithm of both sides of the equation to get:$$ln(k) = ln(A) - \frac{Ea}{RT}$$This equation is linear, with a slope of -Ea/R. We can plot ln(k) vs. 1/T and find the slope of the line to get Ea.Using the data given, we get:$$ln(2.04 	imes 10^{-4}) = ln(A) - \frac{Ea}{8.314 J/mol K 	imes 250 K}$$$$ln(6.78 	imes 10^{-3}) = ln(A) - \frac{Ea}{8.314 J/mol K 	imes 400 K}$$Subtracting the first equation from the second, we get:$$ln(6.78 	imes 10^{-3}) - ln(2.04 	imes 10^{-4}) = \frac{Ea}{8.314 J/mol K} 	imes (400 K - 250 K)$$$$ln(3.32) = \frac{Ea}{8.314 J/mol K} 	imes 150 K$$$$Ea = 19.4 kJ/mol$$Therefore, the activation energy of the reaction is 19.4 kJ/mol.

Question 6

Which of the following describes a reaction mechanism?
I.Consists of a series of elementary steps
II.Reproduces the experimentally determined rate law
III.Is the way the reaction actually occurs

Accepted Answer

A reaction mechanism consists of a series of elementary steps (I) and should reproduce the experimentally determined rate law (II). However, it is a proposed pathway and may not necessarily be the way the reaction actually occurs (III).

Question 7

Chlorine dioxide formed from chlorofluorocarbons was found to catalyze the decomposition of atmospheric ozone. In laboratory experiments, the rate of the catalyzed reaction was measured at different temperatures with the following results. What is the activation energy of this reaction? $$\begin{array} { | l | l | } 
\hline  { \boldsymbol { T } ( \mathbf { K } ) } & { \boldsymbol { k } \left( \boldsymbol { M } ^ { - 1 } \mathrm {~s} ^ { - \mathbf { 1 } } \right) } \
\hline 193 & 34.0 \
\hline 208 & 197 \
\hline
\end{array}$$

Accepted Answer

The activation energy can be calculated using the Arrhenius equation. By taking the natural logarithm of the rate constants and plotting them against the inverse of the temperatures, the slope of the line gives the activation energy. Calculating this from the given data results in an activation energy of approximately 39.1 kJ/mol.

Question 8

The following figure shows Arrhenius plots for four different reactions. Which reaction has the least temperature dependence?

Accepted Answer

The answer of The following figure shows Arrhenius plots for...

Question 9

The high temperatures in an automobile engine cause nitrogen and oxygen to form noxious nitrogen monoxide. Use the following data on the temperature dependence of the rate constant to determine the activation energy for this reaction. $$\begin{array} { | l | l | } 
\hline  { \boldsymbol { T } ( \mathbf { K } ) } & \boldsymbol { k } \left( \boldsymbol { M } ^ { - 1 } \mathrm {~s} ^ { - \mathbf { 1 } } \right) \
\hline 2,200 & 1,800 \
\hline 2,400 & 7,400 \
\hline
\end{array}$$

Accepted Answer

The answer of The high temperatures in an automobile engine...

Question 10

The mechanism for the reaction 2H₂O₂(aq) $\rightarrow$ 2H₂O(l) + O₂(g) in the presence of I^-(aq) is proposed to be: Step 1: H₂O₂(aq) + I^-(aq) $\rightarrow$H₂O(l) + OI^-(aq) Step 2: H₂O₂(aq) + OI^-(aq) $\rightarrow$H₂O(l) + O₂(g) + I^-(aq) Which of the following species is an intermediate?

Accepted Answer

OI^- is an intermediate because it is produced in the first step and consumed in the second step.

Question 11

Which of the following must be true of an intermediate in a reaction mechanism? An intermediate is ________
I.produced by an elementary step
II.consumed in an elementary step
III.not included in the overall balanced reaction equation.

Accepted Answer

An intermediate is produced in one elementary step and consumed in another, and it does not appear in the overall balanced reaction equation.

Question 12

Given the following data for the reaction A $\rightarrow$ B, determine the activation energy, E_a, of the reaction. $$\begin{array} { c c } \boldsymbol { k } ( \boldsymbol { M } / \mathrm { s } ) & \boldsymbol { T } \left( { } ^ { \circ } \mathbf { C } \right) \ 0.282 & 277 \ 0.291 & 627 \end{array}$$

Accepted Answer

The Arrhenius equation is:$$k = Ae^{-Ea/RT}$$where:* k is the rate constant* A is the pre-exponential factor* Ea is the activation energy* R is the gas constant* T is the temperatureTaking the natural logarithm of both sides of the equation gives:$$ln(k) = ln(A) - Ea/RT$$Plotting ln(k) versus 1/T should give a straight line with a slope of -Ea/R.Using the data given, we can calculate the slope of the line:$$slope = \frac{ln(k_2) - ln(k_1)}{1/T_2 - 1/T_1} = \frac{ln(0.291) - ln(0.282)}{1/627 - 1/277} = -369 J/mol$$Therefore, the activation energy is 369 J/mol.

Question 13

A reaction mechanism consists of a series of ________ steps.

Accepted Answer

A reaction mechanism consists of elementary steps, which are individual steps in a reaction that involve a single molecular event, such as a bond breaking or forming. These steps can then be combined to form an overall reaction mechanism.

Question 14

A proposed mechanism for the photodecomposition of ozone in the atmosphere is: Step 1: O₃(g) + hv$\rightarrow$O₂(g) + O(g) Step 2: O₃(g) + O(g) $\rightarrow$2 O₂(g) Which of the following species is an intermediate?

Accepted Answer

An intermediate is a species that is produced in one step and consumed in another. In this mechanism, O is produced in Step 1 and consumed in Step 2, making it an intermediate.

Question 15

Given the following data for the reaction A $\rightarrow$ B, determine the activation energy, E_a, of the reaction. $$\begin{array} { c c } \boldsymbol { k } ( \boldsymbol { M } / \mathbf { s } ) & \boldsymbol { T } ( \mathbf { K } ) \ 0.681 & 500 \ 0.715 & 1,000 \end{array}$$

Accepted Answer

The answer of Given the following data for the reaction...

Question 16

Which of the following statements must be true of an intermediate in a reaction mechanism?
I. Is produced in an elementary step.
II. Is consumed in an elementary step.
III. Is included in the overall balanced reaction equation.

Accepted Answer

According to the definition of an intermediate, it is produced in one elementary step and consumed in a later step, making statement I and II both true. However, an intermediate is not included in the overall balanced reaction equation, which only includes the reactants and products. Therefore, statement III is false. Therefore, the correct answer is D, I and II only.

Question 17

The following figure shows Arrhenius plots for four different reactions. Which reaction has the smallest frequency factor?

Accepted Answer

The answer of The following figure shows Arrhenius plots for...

Question 18

The reaction NO₂(g) + CO(g) $\rightarrow$ NO(g) + CO₂(g) is thought to occur by the following mechanism: Step 1: NO₂(g) + NO₂(g)$\rightarrow$NO₃(g) + NO(g) Step 2: NO₃(g) + CO(g) $\rightarrow$NO₂(g) + CO₂(g) Which of the following species is an intermediate?

Accepted Answer

NO₃ is an intermediate because it is formed in the first step and consumed in the second step, without being seen in the overall reaction equation. NO and CO₂ are both reactants and products, respectively, and do not fit the definition of intermediates.

Question 19

Given the following data for the reaction A $\rightarrow$B, determine the frequency factor, A, of the reaction. $$\begin{array} { c c } 
\boldsymbol { k } ( \boldsymbol { M } / \mathrm { s } ) & \boldsymbol { T } ( \mathbf { K } ) \
0.730 & 250 \
0.739 & 450
\end{array}$$

Accepted Answer

The answer of Given the following data for the reaction...

Question 20

The following figure shows Arrhenius plots for four different reactions. Which reaction has the greatest temperature dependence?

Accepted Answer

The answer of The following figure shows Arrhenius plots for...

Quiz 14: Chemical Kinetics: Reactions in the Air We Breathe

Given the following data for the reaction A $\rightarrow$ B, determine the frequency factor, A, of the reaction. $\begin{array} { c c } \boldsymbol { k } ( \boldsymbol { M } / \mathbf { s } ) & \boldsymbol { T } ( \mathbf { K } ) \\0.681 & 500 \\0.715 & 1,000\end{array}$

Given the following data for the reaction A $\rightarrow$ B, determine the activation energy, E_a, of the reaction. $\begin{array} { c c } \boldsymbol { k } ( \boldsymbol { M } / \mathrm { s } ) & \boldsymbol { T } ( \mathbf { K } ) \\0.730 & 250 \\0.739 & 450\end{array}$

Given the following data for the reaction A $\rightarrow$ B, determine the frequency factor, A, of the reaction. $\begin{array} { c c } \boldsymbol { k } ( \boldsymbol { M } / \mathrm { s } ) & \boldsymbol { T } \left( { } ^ { \circ } \mathbf { C } \right) \\0.282 & 277 \\0.291 & 627\end{array}$

Given the following data for the reaction A $\rightarrow$ B, determine the activation energy, E_a, of the reaction. $\begin{array} { c c } k ( M / s ) & T ( \mathbf { K } ) \\2.04 \times 10 ^ { - 4 } & 250 \\6.78 \times 10 ^ { - 3 } & 400\end{array}$

Which of the following describes a reaction mechanism? I.Consists of a series of elementary steps II.Reproduces the experimentally determined rate law III.Is the way the reaction actually occurs

The following figure shows Arrhenius plots for four different reactions. Which reaction has the least temperature dependence?

Which of the following must be true of an intermediate in a reaction mechanism? An intermediate is ________ I.produced by an elementary step II.consumed in an elementary step III.not included in the overall balanced reaction equation.

Given the following data for the reaction A $\rightarrow$ B, determine the activation energy, E_a, of the reaction. $\begin{array} { c c } \boldsymbol { k } ( \boldsymbol { M } / \mathrm { s } ) & \boldsymbol { T } \left( { } ^ { \circ } \mathbf { C } \right) \\0.282 & 277 \\0.291 & 627\end{array}$

A reaction mechanism consists of a series of ________ steps.

A proposed mechanism for the photodecomposition of ozone in the atmosphere is: Step 1: O₃(g) + hv $\rightarrow$ O₂(g) + O(g) Step 2: O₃(g) + O(g) $\rightarrow$ 2 O₂(g) Which of the following species is an intermediate?

Given the following data for the reaction A $\rightarrow$ B, determine the activation energy, E_a, of the reaction. $\begin{array} { c c } \boldsymbol { k } ( \boldsymbol { M } / \mathbf { s } ) & \boldsymbol { T } ( \mathbf { K } ) \\0.681 & 500 \\0.715 & 1,000\end{array}$

Which of the following statements must be true of an intermediate in a reaction mechanism? I. Is produced in an elementary step. II. Is consumed in an elementary step. III. Is included in the overall balanced reaction equation.

The following figure shows Arrhenius plots for four different reactions. Which reaction has the smallest frequency factor?

The reaction NO₂(g) + CO(g) $\rightarrow$ NO(g) + CO₂(g) is thought to occur by the following mechanism: Step 1: NO₂(g) + NO₂(g) $\rightarrow$ NO₃(g) + NO(g) Step 2: NO₃(g) + CO(g) $\rightarrow$ NO₂(g) + CO₂(g) Which of the following species is an intermediate?

Given the following data for the reaction A $\rightarrow$ B, determine the frequency factor, A, of the reaction. $\begin{array} { c c } \boldsymbol { k } ( \boldsymbol { M } / \mathrm { s } ) & \boldsymbol { T } ( \mathbf { K } ) \\0.730 & 250 \\0.739 & 450\end{array}$

The following figure shows Arrhenius plots for four different reactions. Which reaction has the greatest temperature dependence?

Quiz 14: Chemical Kinetics: Reactions in the Air We Breathe

Which of the following describes a reaction mechanism? I.Consists of a series of elementary steps II.Reproduces the experimentally determined rate law III.Is the way the reaction actually occurs

The following figure shows Arrhenius plots for four different reactions. Which reaction has the least temperature dependence?

Which of the following must be true of an intermediate in a reaction mechanism? An intermediate is ________ I.produced by an elementary step II.consumed in an elementary step III.not included in the overall balanced reaction equation.

A reaction mechanism consists of a series of ________ steps.

A proposed mechanism for the photodecomposition of ozone in the atmosphere is: Step 1: O3(g) + hv →\rightarrow→ O2(g) + O(g) Step 2: O3(g) + O(g) →\rightarrow→ 2 O2(g) Which of the following species is an intermediate?

Which of the following statements must be true of an intermediate in a reaction mechanism? I. Is produced in an elementary step. II. Is consumed in an elementary step. III. Is included in the overall balanced reaction equation.

The following figure shows Arrhenius plots for four different reactions. Which reaction has the smallest frequency factor?

The reaction NO2(g) + CO(g) →\rightarrow→ NO(g) + CO2(g) is thought to occur by the following mechanism: Step 1: NO2(g) + NO2(g) →\rightarrow→ NO3(g) + NO(g) Step 2: NO3(g) + CO(g) →\rightarrow→ NO2(g) + CO2(g) Which of the following species is an intermediate?

The following figure shows Arrhenius plots for four different reactions. Which reaction has the greatest temperature dependence?

A proposed mechanism for the photodecomposition of ozone in the atmosphere is: Step 1: O₃(g) + hv $\rightarrow$ O₂(g) + O(g) Step 2: O₃(g) + O(g) $\rightarrow$ 2 O₂(g) Which of the following species is an intermediate?

The reaction NO₂(g) + CO(g) $\rightarrow$ NO(g) + CO₂(g) is thought to occur by the following mechanism: Step 1: NO₂(g) + NO₂(g) $\rightarrow$ NO₃(g) + NO(g) Step 2: NO₃(g) + CO(g) $\rightarrow$ NO₂(g) + CO₂(g) Which of the following species is an intermediate?