For the reaction X2 + Y + Z $\rarr$ XY + XZ, it is found that the rate equation is rate = k [X2][Y]. Why does the concentration of Z have no effect on the rate

A) The concentration of Z is very small and the others are very large. B) Z must react in a step after the rate determining step. C) Z is an intermediate. D) The fraction of molecules of Z that have very high energies is zero. E) The activation energy for Z to react is very high. A) The concentration of Z is very small and the others are very large. B) Z must react in a step after the rate determining step. C) Z is an intermediate. D) The fraction of molecules of Z that have very high energies is zero. E) The activation energy for Z to react is very high.

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

A) 1.5 * 105 s B) 410 s C) 5.4 * 107 s D) 520 s E) 305 s A) 1.5 * 105 s B) 410 s C) 5.4 * 107 s D) 520 s E) 305 s

The following mechanism has been suggested for the reaction: $\begin{array}{ll} \mathrm{H}_{2} \mathrm{O}_{2}+2 \mathrm{H}^{+}+2 \mathrm{I}^{-} \rightarrow \mathrm{I}_{2}+2 \mathrm{H}_{2} \mathrm{O} \\ \mathrm{H}_{2} \mathrm{O}_{2}+\mathrm{I}^{-} \rightarrow \mathrm{HOI}+\mathrm{OH}^{-} & \mathrm{Slow}\\ \mathrm{OH}^{-}+\mathrm{H}^{+} \rightarrow \mathrm{H}_{2} \mathrm{O} & \mathrm{Fast}\\ \mathrm{HOI}+\mathrm{H}^{+}+\mathrm{I}^{-} \rightarrow \mathrm{I}_{2}+\mathrm{H}_{2} \mathrm{O}& \mathrm{Fast} \end{array}$ Identify the rate law that is consistent with this mechanism.

A) Rate = k[H2O2][I-] B) Rate = k[HOI][OH-] C) Rate = k[OH-][H+] D) Rate = k[HOI][H+][I-] E) Rate = k[H2O2][[I-]2[H+]2 A) Rate = k[H2O2][I-] B) Rate = k[HOI][OH-] C) Rate = k[OH-][H+] D) Rate = k[HOI][H+][I-] E) Rate = k[H2O2][[I-]2[H+]2

The following reaction in aqueous solution was found to be first order in [OH-], first order in [C2H5Br], and inverse first order in Br-.C2H5Br + OH- $\rarr$ C2H5OH + Br- Which one of the following mechanisms is consistent with the observed reaction order

A) C2H5Br $\rarr$C2H5+ + Br- fast C2H5+ + OH- $\rarr$C2H5OH slow B) C2H5Br +H2O $\rarr$C2H5OH + H+ + Br- slow H+ + OH- $\rarr$ H2O fast C) C2H5Br $\rarr$ C2H5+ + Br- slow C2H5+ + OH- $\rarr$C2H5OH fast D) C2H5Br $\rarr$ C2H5+ + Br- slow A) C2H5Br $\rarr$C2H5+ + Br- fast C2H5+ + OH- $\rarr$C2H5OH slow B) C2H5Br +H2O $\rarr$C2H5OH + H+ + Br- slow H+ + OH- $\rarr$ H2O fast C) C2H5Br $\rarr$ C2H5+ + Br- slow C2H5+ + OH- $\rarr$C2H5OH fast D) C2H5Br $\rarr$ C2H5+ + Br- slow

Concerning the rate law, Rate = k[A]2[B], what are appropriate units for the rate constant k

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

Nitrogen pentoxide decomposes by a first-order process yielding N2O4 and oxygen.2N2O5 $\rarr$2N2O4 + O2 At a given temperature, the half-life of N2O5 is 0.90 hr. What is the first-order rate constant for N2O5 decomposition

A) 0.17 hr-1 B) 0.37 hr-1 C) 0.57 hr-1 D) 0.77 hr-1 E) None of the above A) 0.17 hr-1 B) 0.37 hr-1 C) 0.57 hr-1 D) 0.77 hr-1 E) None of the above

The rate law for the reaction 2NO2 + O3 $\rarr$N2O5 + O2 is rate = k[NO2][O3]. Which one of the following mechanisms is consistent with this rate law

A) NO2 + NO2 $\rarr$ N2O4 (fast) N2O4 + O3 $\rarr$N2O5 + O2 (slow) B) NO2 + O3 $\rarr$ NO5 (fast) NO5 + NO5 $\rarr$N2O5 + 5/2O2 (slow) C) NO2 + O3 $\rarr$ NO3 + O2 (slow) NO3 + NO2 $\rarr$N2O5 (fast) D) NO2 + NO2 $\rarr$N2O2 + O2 (slow) A) NO2 + NO2 $\rarr$ N2O4 (fast) N2O4 + O3 $\rarr$N2O5 + O2 (slow) B) NO2 + O3 $\rarr$ NO5 (fast) NO5 + NO5 $\rarr$N2O5 + 5/2O2 (slow) C) NO2 + O3 $\rarr$ NO3 + O2 (slow) NO3 + NO2 $\rarr$N2O5 (fast) D) NO2 + NO2 $\rarr$N2O2 + O2 (slow)

Use the following data to determine the rate law for the reaction shown below.2NO + H2 $\rarr$ N2O + H2O $\begin{array}{lccc} Expt.\# &[\mathrm{NO}]_{0}&\left[\mathrm{H}_{2}\right]_{0}&Initial~ rate \\\hline 1 & 0.021 & 0.065 & 1.46 \mathrm{M} / \mathrm{min} \\ 2 & 0.021 & 0.260 & 1.46 \mathrm{M} / \mathrm{min} \\ 3 & 0.042 & 0.065 & 5.84 \mathrm{M} / \mathrm{min} \end{array}$

A) rate = k[NO] B) rate = k[NO]2 C) rate = k[NO][H2] D) rate = k[NO]2[H2] E) rate = k[NO]2[H2]2 A) rate = k[NO] B) rate = k[NO]2 C) rate = k[NO][H2] D) rate = k[NO]2[H2] E) rate = k[NO]2[H2]2

Chlorine dioxide reacts in basic water to form chlorite and chlorate according to the following chemical equation: 2ClO2(aq) + 2OH-(aq) $\rarr$ ClO2-(aq) + ClO3-(aq) + H2O(l) A kinetic study of this reaction under a certain set of conditions yielded the data below. $\begin{array}{|l|c|c|c|} \hline \operatorname{Exp} & {\left[\mathrm{ClO}_{2}\right](\mathrm{M})} & {\left[\mathrm{OH}^{-}\right](\mathrm{M})} & -\Delta\left[\mathrm{ClO}_{2}\right] / \Delta \mathrm{t}(\mathrm{M} / \mathrm{s}) \\ \hline 1 & 0.0500 & 0.100 & 5.75 \times 10^{-2} \\ \hline 2 & 0.100 & 0.100 & 2.30 \times 10^{-1} \\ \hline 3 & 0.100 & 0.0500 & 1.15 \times 10^{-1} \\ \hline \end{array}$ Which one of the following is the rate law for this reaction

A) rate = k[ClO2][OH-] B) rate = k[ClO2]2[OH-] C) rate = k[ClO2][OH-]2 D) rate = k[ClO2]2[OH-]2 E) rate = k[ClO2]4[OH-] A) rate = k[ClO2][OH-] B) rate = k[ClO2]2[OH-] C) rate = k[ClO2][OH-]2 D) rate = k[ClO2]2[OH-]2 E) rate = k[ClO2]4[OH-]

Exam 13: Chemical Kinetics

The isomerization of methyl isocyanide, CH₃NC $\rarr$ CH₃CN, follows first-order kinetics. The half-lives were found to be 161 min at 199^$\circ$C and 12.5 min at 230^$\circ$C. Calculate the activation energy for this reaction.

(Multiple Choice)

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Question 41

For the reaction X₂ + Y + Z $\rarr$ XY + XZ, it is found that the rate equation is rate = k [X₂][Y]. Why does the concentration of Z have no effect on the rate

(Multiple Choice)

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Question 42

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 Based on the data given, what is the half-life for the disappearance of acetaldehyde

(Multiple Choice)

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Question 43

When acetaldehyde at a pressure of 364 mmHg is introduced into an evacuated 500. mL flask at 518^$\circ$C, the half-life for the second-order decomposition process, CH₃CHO $\rarr$ CH₄ + CO, is 410. s. What will the total pressure in the flask be after 1.00 hour

(Multiple Choice)

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Question 44

At 30^$\circ$C, by how much is a reaction's activation energy decreased by the addition of a catalyst if the catalyst triples the reaction rate

(Multiple Choice)

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Question 45

The following mechanism has been suggested for the reaction: +2+2\rightarrow+2 +\rightarrow+ +\rightarrow ++\rightarrow+ Identify the rate law that is consistent with this mechanism.

(Multiple Choice)

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Question 46

The following reaction in aqueous solution was found to be first order in [OH^-], first order in [C₂H₅Br], and inverse first order in Br^-.C₂H₅Br + OH^- $\rarr$ C₂H₅OH + Br^- Which one of the following mechanisms is consistent with the observed reaction order

(Multiple Choice)

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Question 47

Concerning the rate law, Rate = k[A]²[B], what are appropriate units for the rate constant k

(Multiple Choice)

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Question 48

Nitrogen pentoxide decomposes by a first-order process yielding N₂O₄ and oxygen.2N₂O₅ $\rarr$ 2N₂O₄ + O₂ At a given temperature, the half-life of N₂O₅ is 0.90 hr. What is the first-order rate constant for N₂O₅ decomposition

(Multiple Choice)

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Question 49

The rate law predicted by the following two-step mechanism is rate = k[A][B]. \rightarrow+ slow +\rightarrow+ fast

(True/False)

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Question 50

Concerning the decomposition of A, A $\rarr$ products, which of the following methods could be used to determine the order of the reaction with respect to A I. Plot [A] vs time, ln[A] vs time, and 1/[A] vs time and identify which plot yields a straight line. II. Vary the concentration of A and note by what factor the rate changes. III. Identify if successive half lives of A double, halve, or stay constant.

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Question 51

The rate constant of a first-order reaction, A $\rarr$ products, can be determined from a graph of ln[A] versus t.

(True/False)

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Question 52

Hydrogen peroxide decomposes to water and oxygen gas, and the activation energy for this process is 42 kJ/mol. The hydrogen peroxide formed in biological processes is harmful to tissue, but the enzyme catalase catalyzes the decomposition of hydrogen peroxide by lowering the activation energy to 7.0 kJ/mol. Assuming the frequency factor is the same for both processes and independent of temperature, calculate the temperature required for the uncatalyzed decomposition to proceed at the same rate as the enzyme-catalyzed decomposition at 37^$\circ$C (normal human body temperature).

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Question 53

A city's water supply is contaminated with a toxin at a concentration of 0.63 mg/L. Fortunately, this toxin decomposes to a safe mixture of products by first-order kinetics with a rate constant of 0.27 day^-1. How long will it take for half of the toxin to decompose

(Multiple Choice)

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Question 54

Given that E_a for a certain biological reaction is 48 kJ/mol and that the rate constant is 2.5 *10^-2 s^-1 at 15^$\circ$C, what is the rate constant at 37^$\circ$C

(Multiple Choice)

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Question 55

The rate constant for a certain first-order reaction is 0.40/min. What is the initial rate in mole/L·min, if the initial concentration of the compound involved is 0.50 mol/L

(Multiple Choice)

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Question 56

For the reaction whose rate law is rate = k[X], a plot of which of the following is a straight line

(Multiple Choice)

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Question 57

The rate law for the reaction 2NO₂ + O₃ $\rarr$ N₂O₅ + O₂ is rate = k[NO₂][O₃]. Which one of the following mechanisms is consistent with this rate law

(Multiple Choice)

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Question 58

Use the following data to determine the rate law for the reaction shown below.2NO + H₂ $\rarr$ N₂O + H₂O Expt.\# [ Initial\nobreakspacerate 1 0.021 0.065 1.46/ 2 0.021 0.260 1.46/ 3 0.042 0.065 5.84/

(Multiple Choice)

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Question 59

Chlorine dioxide reacts in basic water to form chlorite and chlorate according to the following chemical equation: 2ClO₂(aq) + 2OH^-(aq) $\rarr$ ClO₂^-(aq) + ClO₃^-(aq) + H₂O(l) A kinetic study of this reaction under a certain set of conditions yielded the data below. Exp () () -\Delta /\Delta(/) 1 0.0500 0.100 5.75\times1 2 0.100 0.100 2.30\times1 3 0.100 0.0500 1.15\times1 Which one of the following is the rate law for this reaction

(Multiple Choice)

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Question 60

Showing 41 - 60 of 131

Exam 13: Chemical Kinetics

The isomerization of methyl isocyanide, CH3NC →\rarr→ CH3CN, follows first-order kinetics. The half-lives were found to be 161 min at 199 ∘\circ∘ C and 12.5 min at 230 ∘\circ∘ C. Calculate the activation energy for this reaction.

For the reaction X2 + Y + Z →\rarr→ XY + XZ, it is found that the rate equation is rate = k [X2][Y]. Why does the concentration of Z have no effect on the rate

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 Based on the data given, what is the half-life for the disappearance of acetaldehyde

When acetaldehyde at a pressure of 364 mmHg is introduced into an evacuated 500. mL flask at 518 ∘\circ∘ C, the half-life for the second-order decomposition process, CH3CHO →\rarr→ CH4 + CO, is 410. s. What will the total pressure in the flask be after 1.00 hour

At 30 ∘\circ∘ C, by how much is a reaction's activation energy decreased by the addition of a catalyst if the catalyst triples the reaction rate

The following mechanism has been suggested for the reaction: +2+2\rightarrow+2 +\rightarrow+ +\rightarrow ++\rightarrow+ Identify the rate law that is consistent with this mechanism.

The following reaction in aqueous solution was found to be first order in [OH-], first order in [C2H5Br], and inverse first order in Br-.C2H5Br + OH- →\rarr→ C2H5OH + Br- Which one of the following mechanisms is consistent with the observed reaction order

Concerning the rate law, Rate = k[A]2[B], what are appropriate units for the rate constant k

Nitrogen pentoxide decomposes by a first-order process yielding N2O4 and oxygen.2N2O5 →\rarr→ 2N2O4 + O2 At a given temperature, the half-life of N2O5 is 0.90 hr. What is the first-order rate constant for N2O5 decomposition

The rate law predicted by the following two-step mechanism is rate = k[A][B]. \rightarrow+ slow +\rightarrow+ fast

The rate constant of a first-order reaction, A →\rarr→ products, can be determined from a graph of ln[A] versus t.

A city's water supply is contaminated with a toxin at a concentration of 0.63 mg/L. Fortunately, this toxin decomposes to a safe mixture of products by first-order kinetics with a rate constant of 0.27 day-1. How long will it take for half of the toxin to decompose

Given that Ea for a certain biological reaction is 48 kJ/mol and that the rate constant is 2.5 *10-2 s-1 at 15 ∘\circ∘ C, what is the rate constant at 37 ∘\circ∘ C

The rate constant for a certain first-order reaction is 0.40/min. What is the initial rate in mole/L·min, if the initial concentration of the compound involved is 0.50 mol/L

For the reaction whose rate law is rate = k[X], a plot of which of the following is a straight line

The rate law for the reaction 2NO2 + O3 →\rarr→ N2O5 + O2 is rate = k[NO2][O3]. Which one of the following mechanisms is consistent with this rate law

Use the following data to determine the rate law for the reaction shown below.2NO + H2 →\rarr→ N2O + H2O Expt.\# [ Initial\nobreakspacerate 1 0.021 0.065 1.46/ 2 0.021 0.260 1.46/ 3 0.042 0.065 5.84/

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The isomerization of methyl isocyanide, CH₃NC $\rarr$ CH₃CN, follows first-order kinetics. The half-lives were found to be 161 min at 199^$\circ$C and 12.5 min at 230^$\circ$C. Calculate the activation energy for this reaction.

For the reaction X₂ + Y + Z $\rarr$ XY + XZ, it is found that the rate equation is rate = k [X₂][Y]. Why does the concentration of Z have no effect on the rate

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 Based on the data given, what is the half-life for the disappearance of acetaldehyde

When acetaldehyde at a pressure of 364 mmHg is introduced into an evacuated 500. mL flask at 518^$\circ$C, the half-life for the second-order decomposition process, CH₃CHO $\rarr$ CH₄ + CO, is 410. s. What will the total pressure in the flask be after 1.00 hour

At 30^$\circ$C, by how much is a reaction's activation energy decreased by the addition of a catalyst if the catalyst triples the reaction rate

The following reaction in aqueous solution was found to be first order in [OH^-], first order in [C₂H₅Br], and inverse first order in Br^-.C₂H₅Br + OH^- $\rarr$ C₂H₅OH + Br^- Which one of the following mechanisms is consistent with the observed reaction order

Concerning the rate law, Rate = k[A]²[B], what are appropriate units for the rate constant k

Nitrogen pentoxide decomposes by a first-order process yielding N₂O₄ and oxygen.2N₂O₅ $\rarr$ 2N₂O₄ + O₂ At a given temperature, the half-life of N₂O₅ is 0.90 hr. What is the first-order rate constant for N₂O₅ decomposition

The rate constant of a first-order reaction, A $\rarr$ products, can be determined from a graph of ln[A] versus t.

A city's water supply is contaminated with a toxin at a concentration of 0.63 mg/L. Fortunately, this toxin decomposes to a safe mixture of products by first-order kinetics with a rate constant of 0.27 day^-1. How long will it take for half of the toxin to decompose

Given that E_a for a certain biological reaction is 48 kJ/mol and that the rate constant is 2.5 *10^-2 s^-1 at 15^$\circ$C, what is the rate constant at 37^$\circ$C

The rate law for the reaction 2NO₂ + O₃ $\rarr$ N₂O₅ + O₂ is rate = k[NO₂][O₃]. Which one of the following mechanisms is consistent with this rate law

Use the following data to determine the rate law for the reaction shown below.2NO + H₂ $\rarr$ N₂O + H₂O Expt.\# [ Initial\nobreakspacerate 1 0.021 0.065 1.46/ 2 0.021 0.260 1.46/ 3 0.042 0.065 5.84/