Question

A zero-order reaction has a half-life ‘t’ at some initial concentration C. If C is reduced to C/4, the value of ‘t’:

• A. Remains same
• B. Becomes 4 times
• C. Becomes one-fourth
• D. Doubles

Answer 1

The correct option is C

Becomes one-fourth

Half life for zero order reaction:
$t_{\frac{1}{2}}=\frac{\left[C_A\right]}{k}$
Given that:
$t=\frac{\left[C_C\right]}{k}$ where t is the initial vaue of half life.
When Concentration reduced to ${\frac{1}{4}}^{th}$ of $C$ then half life will be
$t_{\frac{1}{2}}=\frac{1}{4}\times \frac{C}{k}$
$t_{\frac{1}{2}}=\frac{t}{4}$
Hence, the new value is a quarter of the initial value.