Question

At a certain temperature the rate of this reaction is first order in HI with a rate constant of :0.0632s

Answer 1

Answer : The time taken for the reaction is, 28 s.

Explanation :

Expression for rate law for first order kinetics is given by :

$k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}$

where,

k = rate constant  = 0.0632

t = time taken for the process  = ?

$[A_o]$ = initial amount or concentration of the reactant  = 1.28 M

$[A]$ = amount or concentration left time 't' = $1.28\times \frac{17}{100}=0.2176M$

Now put all the given values in above equation, we get:

$0.0632=\frac{2.303}{t}\log\frac{1.28}{0.2176}$

$t=28s$

Therefore, the time taken for the reaction is, 28 s.