Question

first order reaction takes hundred minutes for completion of 60% of the reaction find the time when 90% of the reaction will be completed​

Answer 1

Answer:

251.41 min

Explanation:

Here Given,

t(1)= 100 min

t(2)= ?

First of all we should calculate the value of rate constant(k) for the 60% completion of the 1st order reaction.

Then put the value of 'k' for the 90% completion of the reaction and get the value of t(2).

We know,

for 60% completion of the 1st order reaction

k=(2.303÷t)×log(a÷a-x)

=>k= (2.303÷100)×log(100÷(100-60))

=>k= 9.16×10^-3 (unit)

then

for 90% completion of the 1st order reaction

k=(2.303÷t)×log(a÷a-x)

=>t= (2.303÷k)×log(a÷a-x)

=>t= (2.303÷9.16×10^-3)×log(100÷(100-90))

=>t= 251.41 min