Thermal decomposition of HCOOH is a first order reaction and the rate constant at T(K) is `4.606xx10^(-1)s^(-1)`. The time required to decompose 90% of initial quantity of HCOOH at T(K) in second is

Options

A. 100
B. 500
C. 1000
D. 50

Answer

B

Explanation

First order reaction
`K=(2.303)/(t) log (A_(0))/(A)`
Given, `" "K=4.606xx10^(-3)s^(-1)`
A=90% `A_(0)`= Initial quantity =100%
`t=(2.303)/(4.606xx10^(-3))log ""(1)/(1-9)`
`t=500 s`