Kinetics

Zero Order

[A]o - [A]t = kt slope = -k

According to the rate law rate = k[H3AsO4][I-][H3O+], an increase in the conc of hydronium ion has what effect on this reaction

the rate of reaction increases

Rate

∆[A]/∆t

The oxidation of iodide ions by arsenic acid in acidic aqueous solution occurs according to the stoichiometry shown above. The experimental rate law of the reaction is rate = k[H3AsO4][I-][H3O+]. What is the order wrt I-?

1

Second Order

1/[A]t - 1/[A]o = kt slope = k

The isomerization of cyclopropane to propylene is a first order process with a half life of 19 mins at 500C. The time it takes for the partial pressure of cyclopropane to decrease from 1.0 atm to 0.125 atm at 500C is closest to...

57 mins

rate = k[M][N]2 The rate of a certain chemical reaction between substances M and N obeys the rate law above. The reaction is first studied with [M] and [N] each 1 x 10^-3 molar. If a new experiment is conducted with [M] and [N] each 2 x 10^-3 molar, the reaction rate will increase by a factor of...

8

Step 1: Ce4+ + Mn2+ -> Ce3+ +Mn3+ Step 2: Ce4+ + Mn3+ -> Ce3+ + Mn4+ Step 3: Mn4+ + Tl+ -> Tl3+ + Mn2+ The proposed steps for a catalyzed reaction between Ce4+ and Tl+ are represented above. The products of the overall catalyzed reaction are...

Ce3+ and Tl3+

(CH3)3CCl + OH- -> (CH3)3COH + Cl- For the reaction represented above, the experimental rate law is given as follows rate = k[(CH3)3CCl] If some solid sodium solid hydroxide is added to a solution that is 0.010 molar in (CH3)3CCl and 0.10 molar in NaOH, which of the following is true?

Both the reaction rate and k remain the same

A reaction was observed for 20 days and the percentage of the reactant remaining after each day was recorded in the table above. Which of the following best describes the order and the half-life of the reaction?

First - 3 days

The graph to the right shows the results of a study of the reaction of X with a large excess of Y to yield Z. The conc of X and Y were measured over a period of time. According to the results, which of the following can be concluded about the rate of law for the reaction under the conditions studied

It is first order in [X]

Intermediates

Produced in one step, used in a following step

Which of the following is a correct statement about reaction order?

Reaction order can be determined only by experiment

Catalysts

Used in one step, produced in a following step

Relatively slow rates of chemical reaction are associated with which of the following?

Strong bonds in reactant molecules

2A + B <-> 2C When the concentration of substance B in the reaction above is doubled, all other factors being held constant, it is found that the rate of the reaction remains unchanged. The most probable explanation for this observation is that...

Substance B is not involved in the rate-determining step of the mechanism, but is involved in subsequent steps

Which of the following must be true for a reaction for which the activation energy is the same for both the forward and the reverse reactions?

delta H for the reaction is zero

First Order

ln[A]t - ln[A]o = -kt slope = -k

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

ln[X] versus time

Nitramide, N2H2O2, decomposes slowly in aqueous solution. This decomposition is believed to occur according to the reaction mechanism above. The rate law for the decomposition of nitramide that is consistent with this mechanism is given by which of the following?

rate = (k[N2H2O2]/[H+])

A possible mechanism for the overall reaction represented above is the following 1: NO + NO -> N2O2 slow 2: N2O2 + O2 -> 2NO2 fast Which of the following rate expressions agrees best with this possible mechanism?

rate = k[NO]2

The initial rate data in the table above were obtained for the reaction represented below. What is the experimental rate law for the reaction?

rate = k[NO][O2]2