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)

$\frac{{{[A]}_{0}}}{2k}$

Answer 2

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. $A_{t}=\frac{[A]_{0}}{2}$ $k=\frac{[A]_{0}-\frac{1}{2}[A]_{0}}{t_{1 / 2}}$ $\because t_{1 / 2}=\frac{0}{2 k}$