Question

A certain first-order reaction a → b is 25% complete in 42 min at 25°c. What is the half-life of the reaction?.

Answer 1

The half-life of the reaction is 101.9 min

First order reaction

When a reaction's pace and reactant concentration are inversely correlated, the process is known as a first-order reaction. To put it another way, the reaction rate doubles when the concentration does. One or two reactants can be present in a first-order reaction, as in the case of the decomposition process.

The half-life of first-order reaction:-

The amount of time it takes for the initial concentration of the reactant(s) to decrease by half is known as the half-life of a chemical reaction (abbreviated as "t1/2").

Calculation:-

a→b

25% reacted means 75% remains

t=42 min

Rate constant

k=(2.303/t)(log a/a-x)

k=(2.303/42)(log 100/100-25 )

k=(0.054) (log 100/75)

k=(0.054)(0.1249)

k=0.0068 per min

half life

t1/2=(0.693/k)

     =(0.693/0.0068)

     =101.9 min

Learn more about first order reaction here :-

brainly.com/question/27754430

#SPJ4