Question

The rate constant for a certain reaction is k = 1.30×10−3 s−1 . If the initial reactant concentration was 0.900 M, what will the concentration be after 10.0 minutes?

Answer 1

Given data: k= 1.30 x 10 (to the power -3) /s, Initial concentration A₀= 0.9 M, t=10 min = 600 s. A_t =? i.e. concentration after any time t i.e. A_t=600. From unit of rate constant it’s clear that the reaction is First Order Reaction.

For First order reaction we know that,

A_t = A₀ x e (to the power –kt)

    = 0.9 x e {to the power [-1.30 x 10(to the power-3) x 600]}

    = 0.41 M

    = 0.41 M

The concentration left after 10 min i.e. 600 s will be 0.41265 . M