The rate constant and half - life of a first order reaction are related to each other as _____.

Options

A. `t_(1//2)=(0.693)/(k)`
B. `t_(1//2)=0.693k`
C. `k=0.693" t"_(1//2)`
D. `kt_(1//2)=(1)/(0.693)`

Answer

A

Explanation

For first order reaction, `k=2.303/tlog"[A_(0)]/[A]`
`t=t_(1//2,)[A_(0)]"//2`,
`k=2.303/t_(1//2)log"([A_(0)])/([A_(0)]//2),k=(2.303)/(t_(1//2))log2`
`k=0.693/t_(1//2)ort_(1//2)=0.693/k`