A first order reaction is 75% complete in 60 min. Find the half-life of the reaction.

Explanation

Step I: To Calculate k.
`[R]_0=100,[R]=100-75=25`
t=60 min, k=?
`k=(2.303)/(t)log([R]_0)/([R])`
`=(2.303)/("60 min")log(100)/(25)=(2.303log4)/("60 min")`
`=2.30(2.303xx0.6021)/(60)min^(-1)`
`=0.0231" min"^(-1)`
Step II : To Calculate `t_(1//2)`
`t_(1//2)=(0.693)/(k)=(0.693)/(0.0231)min`
`=(69.3)/(23.1)` min=30 min