What is half life of a first order reaction if time required to decrease concentration of reactant from 0.4 M to 0.1 M is $x$ hour?

$$ \text { Identify ' } \mathrm{A} \text { ' in the following reaction. } $$

$$ \mathrm{A}+\text { Acetyl chloride } \xrightarrow[\mathrm{AlCl}_3]{\text { anhydrous }} \text { 2-Chloroacetophenone + 4-Chloroacetophenone }$$

Calculate osmotic pressure of 0.1 M aqueous solution of an electrolyte at 300 K if van't Hoff factor is 1.125. $\left[\mathrm{R}=0.0821 \mathrm{~atm} \mathrm{dm}^3 \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\right]$

Which from following gases causes the depletion of ozone layer in upper atmosphere?