The OH radical disproportionates according to the elementary chemical reaction OH + OH → H₂O + O. This reaction is second order in OH. The rate constant for the reaction is 2.1 × 10^-12 cm³/molecule • s at room temperature. If the initial OH concentration is 1.6 × 10¹³ molecules/cm³, what is the first half-life for the reaction?

Question

Quizplus · Accepted Answer

The rate law for the reaction is:Rate = k[OH]^2where k is the rate constant. The half-life of a second-order reaction is given by:t1/2 = 1/(k[OH]0)where [OH]0 is the initial concentration of OH. Substituting the given values into this equation, we get:t1/2 = 1/(2.1 × 10^-12 cm^3/molecule • s * 1.6 × 10^13 molecules/cm^3) = 0.030 s

The OH Radical Disproportionates According to the Elementary Chemical Reaction