A first order reaction is 15% complete in 20 minutes. In what time will the reaction 60% complete ?

Answer

`112.7 min`

Explanation

`t_(15 %) = ( 2.303 )/(k) log ""(1)/((1-0.15)) = ( 2.303 )/(k ) xx 0.07058`
` k= ( 2.303 xx 0.07058 )/( 20 min )= 8.1273 xx 10^(-3) min ^(-1)`
` t_(60%) = ( 2.303 )/( 8.1273 xx 10^(-3)) log"" (1)/((1-0.6 ))= ( 2.303 xx 0.3979 )/( 8.1273 xx 10^(-3))`
`= 112.7 min`