The rate constant for a first order reaction is `4.606 xx 10^(-3) s^(-1)`. The time required to reduce 2.0g of the reactant to 0.2g is:

Options

A. 100s
B. 200s
C. 500s
D. 1000s

Answer

C

Explanation

`k=(2.303)/(t)log"(A_(0))/(A)` (First order rate equation)
`4.606xx10^(-3)=(2.303)/(t)log"(2)/(0.2)`
`t=(2.303)/(4.606xx10^(-3))xxlog10`
`=(10^(3))/(2)=500sec`