If a reaction is first order with a rate constant of 5.48 × 10^-2/sec, how long is required for 3/4 of the initial concentration of reactant to be used up?

Question

Quizplus · Accepted Answer

For a first-order reaction, the time required for a certain fraction of the reactant to be used up can be calculated using the formula t = (1/k) * ln(1/(1-f)), where k is the rate constant and f is the fraction of the reactant used up. For 3/4 of the reactant used up, f = 0.75. Substituting the given rate constant, t = (1/5.48 × 10^-2) * ln(1/(1-0.75)) = 25.3 sec.

If a Reaction Is First Order with a Rate Constant