Question

The rate of reaction in terms of the "rate law expression" includes the rate constant (k), the concentration of the reactants, and the orders of the reaction with respect to the different reactants. Consider the following reaction: A+B→C+D The initial concentrations of the reactants A and B are 0.400 M and 0.290 M, respectively. The rate of reaction is 0.060 M⋅s−1, and the orders of the reaction, with respect to reactants A and B, are 1 and 2, respectively. Determine the rate constant (k) for the reaction using the rate law. Express your answer in M−2⋅s−1 to three significant figures. View Available Hint(s) The rate constant(k) k (k) = nothing M−2⋅s−1

Answer 1

The rate constant (k) for the given reaction can be determined using the rate law expression rate = k[A]^1[B]^2. By substituting the given values, the rate constant is determined to be 0.4 M⁻²⋅s⁻¹.

Step-by-step explanation:

The rate constant (k) for a reaction can be determined using the rate law expression. In the given reaction A + B → C + D, the rate law expression is given as:

rate = k[A]^1[B]^2

The reaction orders with respect to reactants A and B are 1 and 2, respectively. The initial concentrations of A and B are 0.400 M and 0.290 M, respectively. The rate of reaction is 0.060 M⋅s⁻¹. To determine the rate constant (k), we can rearrange the rate law expression:

k = rate / [A]^1[B]^2

Substituting the given values:

k = 0.060 M⋅s⁻¹ / (0.400 M)(0.290 M)^2 = 0.4 M⁻²⋅s⁻¹ (rounded to three significant figures)

Answer 2

1.78 M⁻²s⁻¹

Step-by-step explanation:

Let's consider the following reaction:

A + B → C + D

The reaction order for A is 1 and the reaction order for B is 2.

The rate law is:

r = k.[A].[B]²

where,

r is the rate of the reaction

k is the rate constant

[A] and [B] are the molar concentrations of the reactants

Then, we can find the value of k.

`r=k.[A].[B]^(2) \\k=(r)/([A].[B]^(2) ) =(0.060M.s^(-1) )/((0.400M).(0.290M)^(2) ) =1.78M^(-2) s^(-1)`