Question

Consider the following in respect of zero order reaction
I. $t _{1 / 2}$ is directly proportional to the initial concentration
II. Time taken for the completion of the reaction is twice its $t _{1 / 2}$
III. Concentration of the reactant decreases linearly with time
Which of the statements given above are correct?

• A. I & II only
• B. I & III only
• C. II & III only
• D. I, II & III

Answer 1

Answer: (D)

For zero order
(i) $t_{1 / 2}=\frac{a}{2 K}$
$t _{1 / 2} \propto a$
(ii) $x = Kt$
$K =\frac{ x }{ t } \rightarrow t _{1 / 2}=\frac{ a }{2 \times \frac{ x }{ t }}$
$t _{1 / 2} \Rightarrow \frac{ a \times t }{2 x }$
$\therefore t \Rightarrow \frac{2 t _{1 / 2}}{ a } \times x$
(iii) concentration decreases with time.