Quiz | Chemical Kinetics: Rate Laws

1

What is the rate of the following reaction: 2A + B → C?

- [A]t

[A]t

- 12 [A]t

12 [A]t

A is a reagent and its stochiometric coefficient is 2. Reaction rate of a reagent:
 

1α [reagent]t

α = stochiometric coefficient
[reagent] = concentration of the reagent (in mol.L-1)

 

2

What is the overall order of a reaction with a rate = k [A][B]?

0

1

2

3

The overall order of reaction is the sum of the orders of reaction of all the reactants

3

What are the units of the constant k in the rate of reaction = k [A][B] (concentration in mol.L-1) ?

s

mol-2.L2.s

mol-1.L1.s-1

mol-2.L2.s-1

The rate of reaction is in mol.L-1.s-1 and [A]2 [B] is in mol3.L-3   ⇒    k is in mol-2.L2.s-1

4

What is correct concerning the half-time of a first-order reaction?

t1/2 is independent of the initial concentration of the reactant

t1/2 is proportional to the initial concentration of the reactant

t1/2 is inversely proportional to the initial concentration of the reactant

None of the above

For a first-order reaction:   t1/2 = ln 2k

5

What is correct concerning the half-time of a second-order reaction?

t1/2 is independent of the initial concentration of the reactant

t1/2 is proportional to the initial concentration of the reactant

t1/2 is inversely proportional to the initial concentration of the reactant

None of the above

For a second-order reaction:   t1/2 = 1k [A]0

6

What is the relationship between [A] and t for a first-order reaction?

ln[A] = ln[A]0 + kt

[A][A]0 = e-kt

[A][A]0 = et

1[A] = 1[A]0 + kt

For a first-order reaction:   - [A]t = k [A]

After integrating:    ln [A] = ln [A]0 - kt   ⇒   [A][A]0 = e-kt