Question 1

At 25 ∘\circ∘ C, by what factor is the reaction rate increased by a catalyst that reduces the activation energy of the reaction by 1.00 kJ/mol

Accepted Answer

A)   1.63
B)   123
C)   1.04
D)   1.50
E)   2.53 F) C) and D)
G) D) and E)

Question 2

At 25 ∘\circ∘ C the rate constant for the first-order decomposition of a pesticide solution is 6.40 *10-3 min-1. If the starting concentration of pesticide is 0.0314 M, what concentration will remain after 62.0 min at 25 ∘\circ∘ C

Accepted Answer

A)   1.14 * 10-1 M
B)   47.4 M
C)   -8.72.0 M
D)   2.11 * 10-2 M
E)   2.68* 10-2 M F) A) and B)
G) A) and C)

Question 3

For the following reaction,  Δ\DeltaΔ P(C6H14) / Δ\DeltaΔ t was found to be -6.2 * 10-3 atm/s.C6H14(g)   →\rarr→  C6H6(g)  + 4H2(g)  Determine  Δ\DeltaΔ P(H2) / Δ\DeltaΔ t for this reaction at the same time.

Accepted Answer

A)   6.2 * 10-3 atm/s
B)   1.6 * 10-3 atm/s
C)   2.5 * 10-2 atm/s
D)   -1.6 * 10-3 atm/s
E)   -2.5 * 10-2 atm/s F) A) and B)
G) B) and D)

Question 4

A certain reaction A  →\rarr→  products is second order with respect toA. If it takes 45 min to reduce the concentration of A from 0.350 M to 0.125 M, what is the rate constant for this reaction

Accepted Answer

A)   3.8 x 10-4 M-1min-1
B)   1.9 x 10-3 M-1min-1
C)   5.0 x 10-3 M-1min-1
D)   2.3 x 10-2 M-1min-1
E)   1.1 x 10-1 M-1min-1 F) B) and E)
G) All of the above

Question 5

It is possible for the following overall reaction to consist of a one step mechanism:
2A $\rarr$ products

Accepted Answer

A) True 
 B)False

Question 6

The first-order decomposition, A  →\rarr→  products, has a rate constant of 0.150 s-1. Starting with [A]o = 0.350 M, how much time is required for [A]t = 0.125 M

Accepted Answer

A)   6.86 s
B)   2.98 s
C)   34 s
D)   1.50 s
E)   4.62 s F) A) and E)
G) B) and C)

Question 7

The reaction C4H10  →\rarr→ C2H6 + C2H4 has an activation energy (Ea)  of 350 kJ/mol, and the Ea of the reverse reaction is 260 kJ/mol. Estimate  Δ\DeltaΔ H, in kJ/mol, for the reaction as written above.

Accepted Answer

A)   -90 kJ/mol
B)   +90 kJ/mol
C)   350 kJ/mol
D)   -610 kJ/mol
E)   +610 kJ/mol F) A) and E)
G) B) and D)

Question 8

Which of the following statements is false

Accepted Answer

A)   A catalyst increases the rate of the forward reaction, but does not alter the reverse rate.
B)   A catalyst alters the mechanism of reaction.
C)   A catalyst alters the activation energy.
D)   A catalyst may be altered in the reaction, but is always regenerated.
E)   A catalyst increases the rate of reaction, but is not consumed.F) B) and C)
G) C) and D)

Question 9

It takes 42.0 min for the concentration of a reactant in a first-order reaction to drop from 0.45 M to 0.32 M at 25 ∘\circ∘ C. How long will it take for the reaction to be 90% complete

Accepted Answer

A)   13.0 min
B)   86.0 min
C)   137 min
D)   222 min
E)   284 min F) A) and D)
G) A) and B)

Question 10

The gas phase reaction of nitrogen dioxide and carbon monoxide was found experimentally to be second-order with respect to NO2, and zero-order with respect to CO below 25 ∘\circ∘ C.
NO2 + CO  →\rarr→  NO + CO2 
Which one of the following mechanisms is consistent with the observed reaction order

Accepted Answer

A)   NO2 + 2CO  →\rarr→  N + 2CO2 fast N + NO2  →\rarr→  2NO slow
B)   NO2 + 2CO  →\rarr→ N + 2CO2 slow N + NO2  →\rarr→  2NO fast
C)   NO2 + NO2   →\rarr→  NO3 + NO fast NO3 + CO  →\rarr→ NO2 + CO2 slow
D)   NO2 + NO2   →\rarr→  NO3 + NO slow NO3+CO→NO2+CO2NO_3 + CO \rarr NO_2 + CO_2NO3​+CO→NO2​+CO2​         fast E) None of the above
F) All of the above

Question 11

The reaction 2NO2(g)   →\rarr→  2NO(g)  + O2(g)  is suspected to be second order in NO2. Which of the following kinetic plots would be the most useful to confirm whether or not the reaction is second order

Accepted Answer

A)   A plot of [NO2]-1 vs. t
B)   A plot of ln [NO2]-1 vs. t
C)   A plot of ln [NO2] vs. t
D)   A plot of [NO2]2 vs. t
E)   A plot of [NO2] vs. t F) D) and E)
G) B) and D)

Question 12

Concerning the rate law, Rate = k[A][B], 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/sF) B) and C)
G) C) and D)

Question 13

A reaction was experimentally determined to follow the rate law, Rate = k[A] where k = 0.15 s-1. Starting with [A]o = 0.225M, how many seconds will it take for [A]t = 0.0350M

Accepted Answer

A)   3.4 x 10-2 s
B)   5.3 x 10-3 s
C)   12 s
D)   160 s
E)   1.3 sF) A) and B)
G) C) and D)

Question 14

An increase in the temperature of the reactants causes an increase in the rate of reaction. The best explanation for this behavior is that as the temperature increases,

Accepted Answer

A)   the concentration of reactants increases.
B)   the activation energy decreases.
C)   the collision frequency increases.
D)   the fraction of collisions with total kinetic energy greater than Ea increases.
E)   the activation energy increases.F) B) and E)
G) All of the above

Question 15

For the chemical reaction A  →\rarr→   B + C, a plot of [A]t versus time is found to give a straight line with a negative slope. What is the order of reaction with respect to A

Accepted Answer

A)   zero
B)   first
C)   second
D)   third
E)   Such a plot cannot reveal the order of the reaction. F) None of the above
G) C) and D)

Question 16

A city's water supply is contaminated with a toxin at a concentration of 0.63 mg/L. For the water to be safe for drinking, the concentration of this toxin must be below 1.5 x 10-3 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 the water to be safe to drink

Accepted Answer

A)   2.2 days
B)   2.6 days
C)   20 days
D)   22 days
E)   27 daysF) C) and E)
G) None of the above

Question 17

It is possible for the following overall reaction to consist of a one step mechanism:
2A + B + C $\rarr$ products

Accepted Answer

A) True 
 B)False

Question 18

What is the rate law that corresponds to the data shown for the reaction 2A + B  →arr→  C   Exp.  Initial [A]  Initial [B]  Initial rate 10.0150.0220.12520.0300.0440.50030.0600.0440.50040.0600.0661.125\begin{array}{cccc}	ext { Exp. } & 	ext { Initial [A] } & 	ext { Initial [B] } & 	ext { Initial rate } \1 & 0.015 & 0.022 & 0.125 \2 & 0.030 & 0.044 & 0.500 \3 & 0.060 & 0.044 & 0.500 \4 & 0.060 & 0.066 & 1.125\end{array} Exp. 1234​ Initial [A] 0.0150.0300.0600.060​ Initial [B] 0.0220.0440.0440.066​ Initial rate 0.1250.5000.5001.125​

Accepted Answer

A)   Rate = k[B]0
B)   Rate = k[B]2
C)   Rate = k[B]3
D)   Rate = k[B]
E)   None of the above F) A) and D)
G) A) and C)

Question 19

For the first-order reaction, A $\rarr$ products, if half of the initial concentration of A reacts in 20 min, then the remaining half will completely react in the next 20 min.

Accepted Answer

A) True 
 B)False

Question 20

The reaction A + 2B  →\rarr→  products was found to follow the rate law: rate = k[A]2[B]. Predict by what factor the rate of reaction will increase when the concentration of A is doubled, the concentration of B is tripled, and the temperature remains constant.

Accepted Answer

A)   5
B)   6
C)   12
D)   18
E)   None of these. F) B) and D)
G) C) and D)

Exam 13: Chemical Kinetics

A certain reaction A $\rarr$ products is second order with respect toA. If it takes 45 min to reduce the concentration of A from 0.350 M to 0.125 M, what is the rate constant for this reaction

Correct Answer
verified

The reaction C₄H₁₀ $\rarr$ C₂H₆ + C₂H₄ has an activation energy (E_a) of 350 kJ/mol, and the E_a of the reverse reaction is 260 kJ/mol. Estimate $\Delta$ H, in kJ/mol, for the reaction as written above.

Correct Answer
verified

It is possible for the following overall reaction to consist of a one step mechanism: 2A $\rarr$ products

Correct Answer
verified

Correct Answer
verified

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

Correct Answer
verified

An increase in the temperature of the reactants causes an increase in the rate of reaction. The best explanation for this behavior is that as the temperature increases,

Correct Answer
verified

Which of the following statements is false

Correct Answer
verified

At 25^$\circ$C, by what factor is the reaction rate increased by a catalyst that reduces the activation energy of the reaction by 1.00 kJ/mol

Correct Answer
verified

Correct Answer
verified

For the chemical reaction A $\rarr$ B + C, a plot of [A]_t versus time is found to give a straight line with a negative slope. What is the order of reaction with respect to A

Correct Answer
verified

At 25^$\circ$C the rate constant for the first-order decomposition of a pesticide solution is 6.40 *10^-3 min^-1. If the starting concentration of pesticide is 0.0314 M, what concentration will remain after 62.0 min at 25^$\circ$C

Correct Answer
verified

The gas phase reaction of nitrogen dioxide and carbon monoxide was found experimentally to be second-order with respect to NO₂, and zero-order with respect to CO below 25^$\circ$C. NO₂ + CO $\rarr$ NO + CO₂ Which one of the following mechanisms is consistent with the observed reaction order

Correct Answer
verified

The first-order decomposition, A $\rarr$ products, has a rate constant of 0.150 s^-1. Starting with [A]_o = 0.350 M, how much time is required for [A]_t = 0.125 M

Correct Answer
verified

The reaction A + 2B $\rarr$ products was found to follow the rate law: rate = k[A]²[B]. Predict by what factor the rate of reaction will increase when the concentration of A is doubled, the concentration of B is tripled, and the temperature remains constant.

Correct Answer
verified

The reaction 2NO₂(g) $\rarr$ 2NO(g) + O₂(g) is suspected to be second order in NO₂. Which of the following kinetic plots would be the most useful to confirm whether or not the reaction is second order

Correct Answer
verified

A reaction was experimentally determined to follow the rate law, Rate = k[A] where k = 0.15 s^-1. Starting with [A]_o = 0.225M, how many seconds will it take for [A]_t = 0.0350M

Correct Answer
verified

For the following reaction, $\Delta$ P(C₆H₁₄) / $\Delta$ t was found to be -6.2 * 10^-3 atm/s.C₆H₁₄(g) $\rarr$ C₆H₆(g) + 4H₂(g) Determine $\Delta$ P(H₂) / $\Delta$ t for this reaction at the same time.

Correct Answer
verified

For the first-order reaction, A $\rarr$ products, if half of the initial concentration of A reacts in 20 min, then the remaining half will completely react in the next 20 min.

Correct Answer
verified

It takes 42.0 min for the concentration of a reactant in a first-order reaction to drop from 0.45 M to 0.32 M at 25^$\circ$C. How long will it take for the reaction to be 90% complete

Correct Answer
verified

It is possible for the following overall reaction to consist of a one step mechanism: 2A + B + C $\rarr$ products

Correct Answer
verified

Exam 13: Chemical Kinetics

A certain reaction A →\rarr→ products is second order with respect toA. If it takes 45 min to reduce the concentration of A from 0.350 M to 0.125 M, what is the rate constant for this reaction

Correct AnswerverifiedShow Answer

The reaction C4H10 →\rarr→ C2H6 + C2H4 has an activation energy (Ea) of 350 kJ/mol, and the Ea of the reverse reaction is 260 kJ/mol. Estimate Δ\DeltaΔ H, in kJ/mol, for the reaction as written above.

Correct AnswerverifiedShow Answer

It is possible for the following overall reaction to consist of a one step mechanism: 2A →\rarr→ products

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

An increase in the temperature of the reactants causes an increase in the rate of reaction. The best explanation for this behavior is that as the temperature increases,

Correct AnswerverifiedShow Answer

Which of the following statements is false

Correct AnswerverifiedShow Answer

At 25 ∘\circ∘ C, by what factor is the reaction rate increased by a catalyst that reduces the activation energy of the reaction by 1.00 kJ/mol

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

For the chemical reaction A →\rarr→ B + C, a plot of [A]t versus time is found to give a straight line with a negative slope. What is the order of reaction with respect to A

Correct AnswerverifiedShow Answer

At 25 ∘\circ∘ C the rate constant for the first-order decomposition of a pesticide solution is 6.40 *10-3 min-1. If the starting concentration of pesticide is 0.0314 M, what concentration will remain after 62.0 min at 25 ∘\circ∘ C

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

The first-order decomposition, A →\rarr→ products, has a rate constant of 0.150 s-1. Starting with [A]o = 0.350 M, how much time is required for [A]t = 0.125 M

Correct AnswerverifiedShow Answer

The reaction A + 2B →\rarr→ products was found to follow the rate law: rate = k[A]2[B]. Predict by what factor the rate of reaction will increase when the concentration of A is doubled, the concentration of B is tripled, and the temperature remains constant.

Correct AnswerverifiedShow Answer

The reaction 2NO2(g) →\rarr→ 2NO(g) + O2(g) is suspected to be second order in NO2. Which of the following kinetic plots would be the most useful to confirm whether or not the reaction is second order

Correct AnswerverifiedShow Answer

A reaction was experimentally determined to follow the rate law, Rate = k[A] where k = 0.15 s-1. Starting with [A]o = 0.225M, how many seconds will it take for [A]t = 0.0350M

Correct AnswerverifiedShow Answer

For the following reaction, Δ\DeltaΔ P(C6H14) / Δ\DeltaΔ t was found to be -6.2 * 10-3 atm/s.C6H14(g) →\rarr→ C6H6(g) + 4H2(g) Determine Δ\DeltaΔ P(H2) / Δ\DeltaΔ t for this reaction at the same time.

Correct AnswerverifiedShow Answer

For the first-order reaction, A →\rarr→ products, if half of the initial concentration of A reacts in 20 min, then the remaining half will completely react in the next 20 min.

Correct AnswerverifiedShow Answer

It takes 42.0 min for the concentration of a reactant in a first-order reaction to drop from 0.45 M to 0.32 M at 25 ∘\circ∘ C. How long will it take for the reaction to be 90% complete

Correct AnswerverifiedShow Answer

It is possible for the following overall reaction to consist of a one step mechanism: 2A + B + C →\rarr→ products

Correct AnswerverifiedShow Answer

A certain reaction A $\rarr$ products is second order with respect toA. If it takes 45 min to reduce the concentration of A from 0.350 M to 0.125 M, what is the rate constant for this reaction

Correct Answer
verified

The reaction C₄H₁₀ $\rarr$ C₂H₆ + C₂H₄ has an activation energy (E_a) of 350 kJ/mol, and the E_a of the reverse reaction is 260 kJ/mol. Estimate $\Delta$ H, in kJ/mol, for the reaction as written above.

Correct Answer
verified

It is possible for the following overall reaction to consist of a one step mechanism: 2A $\rarr$ products

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

At 25^$\circ$C, by what factor is the reaction rate increased by a catalyst that reduces the activation energy of the reaction by 1.00 kJ/mol

Correct Answer
verified

Correct Answer
verified

For the chemical reaction A $\rarr$ B + C, a plot of [A]_t versus time is found to give a straight line with a negative slope. What is the order of reaction with respect to A

Correct Answer
verified

At 25^$\circ$C the rate constant for the first-order decomposition of a pesticide solution is 6.40 *10^-3 min^-1. If the starting concentration of pesticide is 0.0314 M, what concentration will remain after 62.0 min at 25^$\circ$C

Correct Answer
verified

Correct Answer
verified

The first-order decomposition, A $\rarr$ products, has a rate constant of 0.150 s^-1. Starting with [A]_o = 0.350 M, how much time is required for [A]_t = 0.125 M

Correct Answer
verified

The reaction A + 2B $\rarr$ products was found to follow the rate law: rate = k[A]²[B]. Predict by what factor the rate of reaction will increase when the concentration of A is doubled, the concentration of B is tripled, and the temperature remains constant.

Correct Answer
verified

The reaction 2NO₂(g) $\rarr$ 2NO(g) + O₂(g) is suspected to be second order in NO₂. Which of the following kinetic plots would be the most useful to confirm whether or not the reaction is second order

Correct Answer
verified

A reaction was experimentally determined to follow the rate law, Rate = k[A] where k = 0.15 s^-1. Starting with [A]_o = 0.225M, how many seconds will it take for [A]_t = 0.0350M

Correct Answer
verified

For the following reaction, $\Delta$ P(C₆H₁₄) / $\Delta$ t was found to be -6.2 * 10^-3 atm/s.C₆H₁₄(g) $\rarr$ C₆H₆(g) + 4H₂(g) Determine $\Delta$ P(H₂) / $\Delta$ t for this reaction at the same time.

Correct Answer
verified

For the first-order reaction, A $\rarr$ products, if half of the initial concentration of A reacts in 20 min, then the remaining half will completely react in the next 20 min.

Correct Answer
verified

It takes 42.0 min for the concentration of a reactant in a first-order reaction to drop from 0.45 M to 0.32 M at 25^$\circ$C. How long will it take for the reaction to be 90% complete

Correct Answer
verified

It is possible for the following overall reaction to consist of a one step mechanism: 2A + B + C $\rarr$ products

Correct Answer
verified