Question

For a first order reaction, the time taken to reduce
concentration from 10. M to 2.5 M is
20 min. The time required to reduce 10 M to 0.625
M is
(1) 40 min
(2) 60 min
(3) 80 min
(4) 160 min
​

Answer 1

Solution :

Time taken to reduce by a factor of

<br>

Time taken to reduce by a factor

<br> i.e.,

<br>

<br> Total time required

.