Question

The rate constant for this first‑order reaction is 0.740 s − 1 0.740 s−1 at 400 ∘ C. 400 ∘C. A ⟶ products A⟶products How long, in seconds, would it take for the concentration of A A to decrease from 0.790 M 0.790 M to 0.230 M? 0.230 M?

Answer 1

Answer:

1.668 S

Step-by-step explanation:

We are given that

$A\rightarrow$Product

For first order reaction,

$t=\frac{1}{k}ln\frac{A_0}{A}$

$t=\frac{2.303}{k}log\frac{A_0}{A}$

Rate constant=k=$0.740s^{-1}$

Temperature=$T=400^{\circ}$

We have to find the time taken by the reaction when concentration of A to decrease from 0.790 M to 0.230 M.

$A_0=0.79 M$

$A=0.230$

Substitute the values then we get

$t=\frac{2.303}{0.740}log\frac{0.79}{0.23}$

$t=1.668 s$

Hence, it would take 1.668 s for the concentration of  A to decrease from 0.790 M to 0.230 M.