A subtance `'A'` decomposes by a first-order reaction starting initially with `[A] = 2.00 m` and after `200 min` `[A] = 0.15 m`. For this reaction what is the value of `k`

Options

A. `1.29xx10^(-2)min^(-1)`
B. `2.29xx10^(-2)min^(-1)`
C. `3.29xx10^(-2)min^(-1)`
D. `4.40xx10^(-2)min^(-1)`

Answer

A

Explanation

Given A(a)=`2.00m`, `t=200` min and `a(a-x)=0.15m`
we know
`k=(2.303)/(t)log.(a)/(a-x)=(2.303)/(200)log.(2.00)/(0.15)`
`=(2.303)/(200)xx(0.301+0.824)=1.29xx10^(-2)min^(-1)`