Question

Consider the following data showing the initial rate of a reaction (A→products) at several different concentrations of A.

[A](M) Initial Rate (M/s)
0.15 0.011
0.30 0.044
0.60 0.177

What is the order of the reaction?Express your answer as an integer.

Write a rate law for the reaction.Rate=k[A]3Rate=kRate=k[A]Rate=k[A]2

Answer 1

(1) order = 2

(2) R = K [A]²

Step-by-step explanation:

Given the reaction:

A--------->Product

The rate constant relation for the reaction is given as:

R(i) = K [A]............(*)

Where R(I) is rate constant at different concentration of A.

Taking the rate constant as R1, R2 and R3 for the different concentrations respectively. Then the following equations results

0.011 = K [0.15] ⁿ.........(1)

0.044 = K [0.30]ⁿ .......(2)

0.177 = K [0.60]ⁿ .........(3)

Dividing (2) by (1) and (3) by (1)

Gives:

0.044/0.011 = [0.3/0.15]ⁿ

4 = 2ⁿ; 2² = 2ⁿ; n = 2

Similarly

0.177/0.011 = [0.60/0.15]ⁿ

16.09 = 4ⁿ

16.09 = 16 (approximately)

4² = 4ⁿ ; n = 2

Hence the order of the reaction is 2.

The rate law is R = K [A]²