It is true that :  

(1) A zero order reaction is a single step reaction.  

(2) A second order reaction is always a multistep reaction.  

(3) A first order reaction is always a single step reaction.

(4) A zero order reaction is a multistep reaction.

What will be the order of the reaction for hydrolysis of methyl acetate with $\mathrm{NaOH}$ by using the data provided?

Time $\left(\min \right) 0 5 10 15$
Volume of acid $\left(\mathrm{mL}\right) 10.12 6.24 1.40 0.981$

For the chemical reaction

$2{\mathrm{O}}_3⟶3{\mathrm{O}}_2$, the reaction proceeds as follows

${\mathrm{O}}_3\rightleftharpoons {\mathrm{O}}_2+\mathrm{O}$ (Fast)

$\mathrm{O}+{\mathrm{O}}_3⟶2{\mathrm{O}}_2$, (Slow)

the rate law expression should be given as

$\mathrm{n}=$ order of reaction

For a reaction $2{\mathrm{H}}_2{\mathrm{O}}_2$

$2{\mathrm{H}}_2{\mathrm{O}}_2\underset{\mathrm{Alkaline} \mathrm{medium}}{\overset{{\mathrm{I}}^{-}}{\to }}2{\mathrm{H}}_2\mathrm{O}+{\mathrm{O}}_2$

The proposed mechanism is as given below:

1. ${\mathrm{H}}_2{\mathrm{O}}_2+{\mathrm{I}}^{-}\to {\mathrm{H}}_2\mathrm{O}+{\mathrm{IO}}^{-}$ (slow)

2. ${\mathrm{H}}_2{\mathrm{O}}_2+{\mathrm{IO}}^{-}\to {\mathrm{H}}_2\mathrm{O}+{\mathrm{I}}^{-}+{\mathrm{O}}_2$ (fast)

 Write the overall order of a reaction.