Question

If 'a' is the initial concentration of reaction, then half-life period of a reaction of $n^{th}$ order is:

• A. ${\alpha }^n$
• B. ${\alpha }^{n-1}$
• C. ${\alpha }^{1-n}$
• D. ${\alpha }^{n+1}$

Answer 1

Answer: (C)

${\alpha }^{1-n}$

Relation between half - life period of a reaction and initial concentration is as follows : $t^{1/2}\propto \frac{1}{a^{n-1}}$

for first order reaction (Half life $\propto a^0$ )

for second order reaction (Half life $\propto 1/a$ )

for third order reaction (Half life$\propto 1/a^2$)