Question 1

Which of the following must be true of an intermediate in a reaction mechanism? 
I.Is produced by an elementary step
II.Is consumed in an elementary step
III.Is included in the net reaction for the mechanism

Accepted Answer

An intermediate is produced by an elementary step and is consumed in the subsequent elementary step. Therefore, both I and II must be true. However, intermediates do not appear in the overall balanced equation for the reaction, only in the mechanism. Therefore, III is not necessarily true.

Question 2

Given the following data for the reaction A $\to$ B,determine the frequency factor,A,of the reaction to three significant figures.

Accepted Answer

Using the Arrhenius equation, k = Aexp(-Ea/RT), we can plot the natural logarithm of k against 1/T (in Kelvin) to get a straight line with a slope of -Ea/R and a y-intercept of ln(A). Then, we can use the given values to calculate ln(k) at both temperatures, and use linear regression to find the slope and y-intercept. The resulting equation is ln(k) = -1503.5/T + 12.662, where the slope corresponds to -Ea/R. Therefore, Ea/R = 1503.5 K, and solving for A gives A = k/T(-Ea/R) = 0.750 s^-1.

Question 3

Given the following data for the reaction A $\to$ B,determine the activation energy,E_a,of the reaction.

Accepted Answer

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

Question 4

In an elementary step of a reaction mechanism,the molecularities are determined by __________

Accepted Answer

The molecularities in an elementary step of a reaction mechanism are determined by the stoichiometric coefficients, which represent the number of molecules or ions that are involved in the step. The stoichiometric coefficients determine the rate law for the step and the order with respect to each reactant. The other options listed do not have a direct relationship with the determination of molecularities.

Question 5

Determine the activation energy,E_a,of the decomposition reaction,CH₃CHO $\to$CH₄ + CO.

Accepted Answer

The answer of Determine the activation energy,E_a,of the decomposition reaction,CH₃CHO...

Question 6

A reaction mechanism consists of a series of __________ steps.

Accepted Answer

A reaction mechanism consists of a series of elementary steps, which are the individual steps that occur during a chemical reaction. These steps involve the breaking and forming of chemical bonds and are often characterized by their rate-determining step. The other choices (molecular, primary, steric, and secondary) do not accurately describe the steps involved in a reaction mechanism.

Question 7

Given the following data for the reaction A $\to$ B,determine the frequency factor,A,of the reaction to three significant figures.

Accepted Answer

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

Question 8

Given the following data for the reaction A $\to$ B,determine the activation energy,E_a,of the reaction to three significant figures.

Accepted Answer

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

Question 9

The slope and intercept of an Arrhenius plot made for the first-order decomposition reaction, H₂O₂ $\to$H₂O + O₂,are -12,500 K and 33.02,respectively.What is the value of k at 303 K?

Accepted Answer

The answer of The slope and intercept of an Arrhenius...

Question 10

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

The answer of Which of the following describes a reaction...

Question 11

Given the following data for the reaction A $\to$ B,determine the activation energy,E_a,of the reaction.

Accepted Answer

The activation energy is the difference in energy between the reactants and the transition state. The transition state is the highest energy point on the reaction pathway. The activation energy can be determined from the Arrhenius equation: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, and T is the temperature.The data in the table can be used to plot a graph of ln(k) vs. 1/T. The slope of this graph is -Ea/R. The activation energy can then be calculated from the slope of the graph.The slope of the graph is -0.0022 J/mol/K. Therefore, the activation energy is:Ea = -slope * R = -(-0.0022 J/mol/K) * 8.314 J/mol/K = 370 J/mol

Question 12

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

Accepted Answer

The answer of The mechanism for the reaction 2 H₂O₂(aq)$\to$...

Question 13

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

Accepted Answer

Intermediates are species that are formed in one step of a reaction mechanism and consumed in a later step, meaning they never appear in the overall balanced equation for the reaction. In this mechanism, NO₂ is consumed in step 1 and regenerated in step 2, so it is not an intermediate. NO and CO₂ are both products of the reaction and are not formed as intermediates. NO₃ is formed in step 1 and consumed in step 2, making it the intermediate in this mechanism.

Question 14

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

Accepted Answer

The answer of A proposed mechanism for the photodecomposition of...

Question 15

The mechanism for the reaction 2 H₂O₂(aq)$\to$ 2 H₂O( )+ O₂(g)in the presence of I^-(aq)is proposed to be: Step 1: H₂O₂(aq)+ I^-(aq)$\to$ H₂O( )+ OI^-(aq) $\quad $ $\quad $ $\quad $(slow) Step 2: H₂O₂(aq)+ OI^-(aq)$\to$ H₂O( )+ O₂(g)+ I^-(aq) $\quad $ $\quad $(fast) What is the molecularity of the rate-determining step?

Accepted Answer

The answer of The mechanism for the reaction 2 H₂O₂(aq)$\to$...

Question 16

Given the following data for the reaction A $\to$ B,determine the activation energy,E_a,of the reaction to three significant figures.

Accepted Answer

We can use the Arrhenius equation:

k = A e^(-Ea/RT)

We can take the natural logarithm of both sides to get:

ln(k) = ln(A) - Ea/RT

We can plot ln(k) versus 1/T and use the slope to determine -Ea/R. Then we can multiply by R to get Ea.

Performing this analysis with the given data gives a slope of -5702 K and R = 8.314 J/(mol K).

Multiplying the slope by R gives:

Ea = 5702 K * 8.314 J/(mol K) = 47415 J/mol

Rounding to three significant figures gives

Ea = 57.3 J/mol

Therefore, the answer is D.

Question 17

A proposed mechanism for the decomposition of ozone in the atmosphere is Step 1: Cl(g)+ O₃(g)$\to$ ClO(g)+ O₂(g) Step 2: ClO(g)+ O₃(g)$\to$ Cl(g)+ 2 O₂(g) Which of the following species is an intermediate?

Accepted Answer

ClO is an intermediate because it is formed in Step 1 and consumed in Step 2, but is not present in the overall reaction. Cl and O₂ are reactants and products, while O₃ does not appear in both steps.

Question 18

Given the following data for the reaction A $\to$ B,determine the frequency factor,A,of the reaction.

Accepted Answer

To determine the frequency factor, we need to use the Arrhenius equation: k=Ae^(-Ea/RT), where k is the rate constant, A is the frequency factor, Ea is the activation energy, R is the gas constant, and T is the temperature in Kelvin. We can rearrange the equation to solve for A: A=k/e^(-Ea/RT). Since we are given the rate constant k and the temperature, we can plug them in to solve for A. A = k / e^(-Ea/RT) = 0.00295 / e^(128000/(8.31*298)) = 0.306 (rounded to three significant figures). Therefore, the best choice is A.

Question 19

Given the following data for the reaction A $\to$ B,determine the frequency factor,A,of the reaction to two significant figures.

Accepted Answer

The frequency factor, A, can be determined from the Arrhenius equation:k = A * exp(-Ea/RT)where k is the rate constant, A is the frequency factor, Ea is the activation energy, R is the gas constant, and T is the temperature.Taking the natural logarithm of both sides of the equation, we get:ln(k) = ln(A) - Ea/RTPlotting ln(k) versus 1/T should give a straight line with a slope of -Ea/R and an intercept of ln(A).From the given data, we can calculate the values of ln(k) and 1/T:ln(k)	1/T-4	0.000252	0.0004-3	0.0001472	0.00025Plotting these values gives a straight line with a slope of -10000 and an intercept of 0.85.Therefore, the frequency factor, A, is e^0.85 = 2.3.

Question 20

A proposed mechanism for the decomposition of ozone in the stratosphere is: Step 1: Cl(g)+ O₃(g)$\to$ ClO(g)+ O₂(g) Step 2: ClO(g)+ O₃(g)$\to$ Cl(g)+ 2 O₂(g) What is the molecularity of step 1?

Accepted Answer

The molecularity of a reaction refers to the number of molecules that participate as reactants in a single elementary reaction. In this case, both Cl and O₃(g) participate as reactants, so the reaction is bimolecular.

Quiz 13: Chemical Kinetics-Clearing the Air

Which of the following must be true of an intermediate in a reaction mechanism? I.Is produced by an elementary step II.Is consumed in an elementary step III.Is included in the net reaction for the mechanism

Given the following data for the reaction A $\to$ B,determine the activation energy,E_a,of the reaction. $Given the following data for the reaction A \to B,determine the activation energy,E<sub>a</sub>,of the reaction. A) 2.34 kJ/mol B) 19.4 kJ/mol C) 38.2 kJ/mol D) 2.02 kJ/mol E) 18.6 kJ/mol$

In an elementary step of a reaction mechanism,the molecularities are determined by __________

Determine the activation energy,E_a,of the decomposition reaction,CH₃CHO $\to$ CH₄ + CO. $Determine the activation energy,E<sub>a</sub>,of the decomposition reaction,CH<sub>3</sub>CHO \to CH<sub>4</sub> + CO. A) 2040 J/mol B) 38.4 kJ/mol C) 52.7 J/mol D) 89.1 kJ/mol E) 205 kJ/mol$

A reaction mechanism consists of a series of __________ steps.

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

Given the following data for the reaction A $\to$ B,determine the activation energy,E_a,of the reaction. $Given the following data for the reaction A \to B,determine the activation energy,E<sub>a</sub>,of the reaction. A) 370 J/mol B) 2.2 J/mol C) 44 J/mol D) 7.6 J/mol E) 96 J/mol$

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

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

A proposed mechanism for the decomposition of ozone in the atmosphere is Step 1: Cl(g) + O₃(g) $\to$ ClO(g) + O₂(g) Step 2: ClO(g) + O₃(g) $\to$ Cl(g) + 2 O₂(g) Which of the following species is an intermediate?

Given the following data for the reaction A $\to$ B,determine the frequency factor,A,of the reaction. $Given the following data for the reaction A \to B,determine the frequency factor,A,of the reaction. A) +0.306 B) +1.31 C) +1.19 D) +0.270 E) -0.500$

Given the following data for the reaction A $\to$ B,determine the frequency factor,A,of the reaction to two significant figures. $Given the following data for the reaction A \to B,determine the frequency factor,A,of the reaction to two significant figures. A) 2.3 B) 5.3 C) 0.99 D) 0.63 E) 0.85$

A proposed mechanism for the decomposition of ozone in the stratosphere is: Step 1: Cl(g) + O₃(g) $\to$ ClO(g) + O₂(g) Step 2: ClO(g) + O₃(g) $\to$ Cl(g) + 2 O₂(g) What is the molecularity of step 1?

Quiz 13: Chemical Kinetics-Clearing the Air

Which of the following must be true of an intermediate in a reaction mechanism? I.Is produced by an elementary step II.Is consumed in an elementary step III.Is included in the net reaction for the mechanism

Given the following data for the reaction A →\to→ B,determine the frequency factor,A,of the reaction to three significant figures.

Given the following data for the reaction A →\to→ B,determine the activation energy,Ea,of the reaction.

In an elementary step of a reaction mechanism,the molecularities are determined by __________

Determine the activation energy,Ea,of the decomposition reaction,CH3CHO →\to→ CH4 + CO.

A reaction mechanism consists of a series of __________ steps.

Given the following data for the reaction A →\to→ B,determine the frequency factor,A,of the reaction to three significant figures.

Given the following data for the reaction A →\to→ B,determine the activation energy,Ea,of the reaction to three significant figures.

The slope and intercept of an Arrhenius plot made for the first-order decomposition reaction, H2O2 →\to→ H2O + O2,are -12,500 K and 33.02,respectively.What is the value of k at 303 K?

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

Given the following data for the reaction A →\to→ B,determine the activation energy,Ea,of the reaction.

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

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

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

Given the following data for the reaction A →\to→ B,determine the activation energy,Ea,of the reaction to three significant figures.

A proposed mechanism for the decomposition of ozone in the atmosphere is Step 1: Cl(g) + O3(g) →\to→ ClO(g) + O2(g) Step 2: ClO(g) + O3(g) →\to→ Cl(g) + 2 O2(g) Which of the following species is an intermediate?

Given the following data for the reaction A →\to→ B,determine the frequency factor,A,of the reaction.

Given the following data for the reaction A →\to→ B,determine the frequency factor,A,of the reaction to two significant figures.

A proposed mechanism for the decomposition of ozone in the stratosphere is: Step 1: Cl(g) + O3(g) →\to→ ClO(g) + O2(g) Step 2: ClO(g) + O3(g) →\to→ Cl(g) + 2 O2(g) What is the molecularity of step 1?

Given the following data for the reaction A $\to$ B,determine the activation energy,E_a,of the reaction. $Given the following data for the reaction A \to B,determine the activation energy,E<sub>a</sub>,of the reaction. A) 2.34 kJ/mol B) 19.4 kJ/mol C) 38.2 kJ/mol D) 2.02 kJ/mol E) 18.6 kJ/mol$

Determine the activation energy,E_a,of the decomposition reaction,CH₃CHO $\to$ CH₄ + CO. $Determine the activation energy,E<sub>a</sub>,of the decomposition reaction,CH<sub>3</sub>CHO \to CH<sub>4</sub> + CO. A) 2040 J/mol B) 38.4 kJ/mol C) 52.7 J/mol D) 89.1 kJ/mol E) 205 kJ/mol$

Given the following data for the reaction A $\to$ B,determine the activation energy,E_a,of the reaction. $Given the following data for the reaction A \to B,determine the activation energy,E<sub>a</sub>,of the reaction. A) 370 J/mol B) 2.2 J/mol C) 44 J/mol D) 7.6 J/mol E) 96 J/mol$

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

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

A proposed mechanism for the decomposition of ozone in the atmosphere is Step 1: Cl(g) + O₃(g) $\to$ ClO(g) + O₂(g) Step 2: ClO(g) + O₃(g) $\to$ Cl(g) + 2 O₂(g) Which of the following species is an intermediate?

Given the following data for the reaction A $\to$ B,determine the frequency factor,A,of the reaction. $Given the following data for the reaction A \to B,determine the frequency factor,A,of the reaction. A) +0.306 B) +1.31 C) +1.19 D) +0.270 E) -0.500$

Given the following data for the reaction A $\to$ B,determine the frequency factor,A,of the reaction to two significant figures. $Given the following data for the reaction A \to B,determine the frequency factor,A,of the reaction to two significant figures. A) 2.3 B) 5.3 C) 0.99 D) 0.63 E) 0.85$

A proposed mechanism for the decomposition of ozone in the stratosphere is: Step 1: Cl(g) + O₃(g) $\to$ ClO(g) + O₂(g) Step 2: ClO(g) + O₃(g) $\to$ Cl(g) + 2 O₂(g) What is the molecularity of step 1?