A first-order reaction is 40.0% complete at the end of 48.1 minutes.What is the value of the rate constant (in min^-¹)?

Question

Quizplus · Accepted Answer

We can use the equation for the first-order reaction:

ln([A]0/[A]) = kt

where [A]0 is the initial concentration of the reactant, [A] is the concentration at time t, k is the rate constant, and t is time.

If the reaction is 40% complete, it means that [A]/[A]0 = 0.6. Substituting this into the equation above, we get:

ln(1/0.6) = k(48.1)

Solving for k, we get:

k = ln(1/0.6)/48.1 = 1.06 min^-1

Therefore, the answer is B.

A First-Order Reaction Is 40 ×\times× 10-2 B)1 ×\times× 10-2 C)94