In which of the following reactions, hydrogen is oned the products?

I. $\mathrm{NaBH}_4+\mathrm{I}_2 \longrightarrow$

II. $\mathrm{BF}_3+\mathrm{NaH} \xrightarrow{450 \mathrm{~K}}$

III. $\mathrm{BF}_3+\mathrm{LiAlH}_4 \longrightarrow$

IV. $\mathrm{B}_2 \mathrm{H}_6+\mathrm{NH}_3 \xrightarrow{\text { heat }}$

The correct statements among the following are

(i) saline hydrides produce $\mathrm{H}_2$ gas when reacted with water

(ii) presently $\sim 77 \%$ of the industrial dihydrogen is produced from coal

(iii) commercially marketed $\mathrm{H}_2 \mathrm{O}_2$ contains $3 \% \mathrm{H}_2 \mathrm{O}_2$

Two statements are given below :

I. In dry cleaning, the solvent $\mathrm{Cl}_2 \mathrm{C}=\mathrm{CCl}_2$ was earlier used and now it is replaced by liquefied $\mathrm{CO}_2$

II. In bleaching of paper, $\mathrm{H}_2 \mathrm{O}_2$ was used earlier and now it is replaced by chlorine gas. Correct anwer is

Calcium carbide $$+\mathrm{D}_2 \mathrm{O} \longrightarrow \underline{X}+\mathrm{Ca}(\mathrm{OD})_2$$. The hybridisation of carbon atom(s) in $$X$$

What are $$X$$ and $$Y$$ respectively in the following reactions?

$$\begin{aligned} & \underline{X}+D_2 \mathrm{O} \longrightarrow C_2 D_2+P \\ & \underline{Y}+D_2 \mathrm{O} \longrightarrow C D_4+Q \end{aligned}$$