Henry's law is valid for

(A) ammonia gas dissolution in water

(B) $\mathrm{O}_2$ gas dissolution in unsaturated blood

(C) $\mathrm{O}_2$ dissolution in water

(D) $\mathrm{CO}_2$ dissolution in water

On passing a current of 1.2 A through a solution of salt of copper for $40 \mathrm{~min}, 0.96 \mathrm{~g}$ of copper was deposited. The equivalent weight of copper in g is

Half-life periods for a reaction at initial concentrations of 0.1 M and 0.01 M are 5 and 50 minutes, respectively. The order of reaction is

Catalysts in the following reactions are

(I) $\mathrm{CH}_3 \mathrm{COOCH}_3(l)+\mathrm{H}_2 \mathrm{O}(l)\longrightarrow \mathrm{CH}_3 \mathrm{COOH}(a q)+\mathrm{CH}_3 \mathrm{OH}(l)$

(II) $2 \mathrm{SO}_2(\mathrm{~g}) \longrightarrow 2 \mathrm{SO}_3(\mathrm{~g})$

(III) $2 \mathrm{SO}_2(\mathrm{~g})+\mathrm{O}_2(\mathrm{~g}) \longrightarrow 2 \mathrm{SO}_3(\mathrm{~g})$

(IV) $\mathrm{N}_2(\mathrm{~g})+3 \mathrm{H}_2(\mathrm{~g}) \longrightarrow 2 \mathrm{NH}_3(\mathrm{~g})$