Question

A certain first order reaction has a half-life of 54.3 s. How long will it take (in s) for the reactant concentration to decrease from 6.50 M to 2.27 M

Answer 1

`t=82.2s`

Step-by-step explanation:

From the question we are told that:

Half life
`t_(1/2)=54.3s`

Change in concentration
`\triangle conc=6.50 M to 2.27 M`

Generally the equation for half life is mathematically given by

`k=(2.303)/(t)*log(C_1)/(C_2)`

Where

`K=(0.693)/(t_(1/2))`

`K=(0.693)/(54.3)`

`K=0.0128`

Therefore

`0.0128=(2.303)/(t)*log(6.50)/(2.27)`

`t=82.2s`