Question

For a zero order reaction, $A \longrightarrow P, t_{1 / 2}$ is (k is rate constant)

• A. $ \frac{{{[A]}_{0}}}{2k} $
• B. $ \frac{\text{In}\,2}{k} $
• C. $ \frac{1}{k{{[A]}_{0}}} $
• D. $ \frac{\text{In}\,2}{{{[A]}_{0}}k} $

Answer 1

Answer: (A)

For zero order reaction,
Rate constant $k=\frac{[A]_{0}-[A]_{t}}{t}$
Here, $A_{0}=$ initial concentration of reactant
$A_{t}=$ concentration of reactant after t time.
If half-life period is $t_{1 / 2}$. Initial amount $\left(A_{0}\right)$ will become half.
$A_{t}=\frac{[A]_{0}}{2}$
$k=\frac{[A]_{0}-\frac{1}{2}[A]_{0}}{t_{1 / 2}} $
$\because t_{1 / 2}=\frac{0}{2 k}$