Question

For a zero order reaction, $A⟶P,t_{1/2}$ 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.
$A_t=\frac{[A{]}_0}{2}$
$k=\frac{[A{]}_0-\frac{1}{2}[A{]}_0}{t_{1/2}}$
$\because t_{1/2}=\frac{0}{2k}$