If the half life period for a reaction in A is 100 min . How long will it take [A] to reach 25 % of its initial concentration ?

Options

A. 50 min
B. 250 min
C. 200 min
D. 500 min

Answer

C

Explanation

( C) K `= (0.693)/(100) = 6.93 xx10^(-3)`
` t= (2.303)/(6.93xx10^(-3)) "log" ([A]_(0))/(0.25[A]_(0))`
`= (2.303)/(6.93xx10^(-3))"log"4`
`= (2.303)/(6.93xx10^(-3))xx0.6020`
=200 min