Question

The concentration of a chemical degrades in water according to first-order kinetics. The degradation constant is 0.2 day−1. If the initial concentration is 100.0 mg · L−1, how many days are required for the con- centration to reach 0.14 mg · L−1?

Answer 1

3566.4 days

Step-by-step explanation:

The reaction follows a first-order

Rate = kC = change in concentration/time

k = 0.2 day^-1

C = 0.14 mg.L^-1

Co = 100 mg.L^-1

0.2×0.14 = 100 - 0.14/t

t = 99.86/0.028 = 3566.4 days