A biochemist studying the breakdown in soil of the insecticide DDT finds that it decays by a first order reaction with a rate constant, k , of 0.0578 yr^{- 1}. How long does it take DDT to decay from 295 ppbm tO₅ 0.0 ppbm?

Question

Quizplus · Accepted Answer

For a first-order reaction, the time taken for a substance to decay to a certain concentration can be calculated using the formula: t = (1/k) * ln([A]₀/[A]). Here, [A]₀ is the initial concentration, and [A] is the final concentration. Since the final concentration is 50.0 ppbm, the calculation is: t = (1/0.0578) * ln(295/50) ≈ 30.7 years.

A Biochemist Studying the Breakdown in Soil of the Insecticide