A substance `''A''` decomposes in solution following the first order kinetics. Flask `I` contains `1L` of `1 M` solution of `A` and falsk `II` contains `100 mL` of `0.6 M` solution. After `8 hr`, the concentration, of `A` in flask `I` becomes `0.25 M`. What will be the time for concentration of `A` in flask `II` to become `0.3 M` ?

Options

A. `0.4` hr
B. `2.4` hr
C. `4.0` hr
D. unpredictable as rate constant is not given

Answer

C

Explanation

From the date of 1st falsk, 3/4th of A disappears in 8 hrs.
`therefore 1//2` of A will disappear in 4 hrs.