The half-life of a first order reaction is 30 min.
How long would be required for 25% of the reactant to be decomposed ?

Answer

`12.45 min`

Explanation

`t_(25%) = ( 2.303 )/(k) log ""(1)/( 1-f)`
`=( 2.303 )/( k ) log "" (1)/((1-0.25)) = ( 2.303 )/(k ) log"" (1)/(0.75 )`
`or t_(25 %) =( 2.303 )/(0.0231 ) xx 0.1249 = 12.45 min`