Question

A chemical reaction that is first-order in X is observed to have a rate constant of 1.50 × 10–2 s–1. If the initial concentration of X is 1.0 M, what is the concentration of X after 196 s?

Answer 1

Answer:

0.053 M is the concentration of X after 196 seconds.

Explanation:

Initial concentration of the X = $[A_o]=1.0 M$

Time taken by the sample, t = 196 s

Final concentration of the X after t = [A] =?

Rate constant of the reaction = k = $1.50\times 10^{-2} s^{-1}$

Formula used :

$[A]=[A_o]\times e^{-kt}$

where,

Now put all the given values in this formula, we get

$[A]=[1.0M]\times e^{-1.50\times 10^{-2} s^{-1}\times 196 s}$

$[A]=0.053 M$

0.053 M is the concentration of X after 196 seconds.