Question

If in 1st order of reaction 75 %of reaction is completed in 4 hrs. Then how much time is required to complete 87.5 of reaction

Answer 1

For completing 75% of the reaction it takes 4 hours i.e. 240 minutes.

So by unitary method,

For completing 1% it will take 240/75 minutes.

And for completing 87.5% reaction it will take 240/75*87.5 minutes.

=280 minutes = 4.4 hours = 4 hours 40 minutes.