Question

Which of the following expressions is correct for zero order and first order respectively (where $a$ is initial concentration)

• A. $t_{1/2}\propto a;t_{1/2}\propto \frac{1}{a}$
• B. $t_{1/2}\propto a;t_{1/2}\propto a^0$
• C. $t_{1/2}\propto a^0;t_{1/2}\propto a$
• D. $t_{1/2}\propto a;t_{1/2}\propto \frac{1}{a^2}$

Answer 1

The correct option is B $t_{1/2}\propto a;t_{1/2}\propto a^0$

For zero order reaction, $t_{1/2}=\frac{a}{2k}\Rightarrow t_{1/2}\propto a$

For first order reaction, $t_{1/2}=\frac{0.693}{k}\Rightarrow t_{1/2}\propto a^0$