Question

`99%` at a first order reaction was completed in `32 min`. When will `99.9%` of the reaction complete.
A. `48 min`
B. `46 min`
C. `50 min`
D. `45 min`

Answer 1

Correct Answer - A
`K xx 32 = ln ((100)/(1))` …(i)
`K xx t = ln((100)/(0.1))` …(ii)
eq. `(ii)//(i)`
`(t)/(32) = (3 ln 10)/(2 ln 10)`
`t = 48 min`