Which from following substances acts as a base when reacted with water?

Which from following polymers is classified as fibres?

What type of solution is the iodine in air?

Identify ' $Y$ ' in the following reaction.

$$\mathrm{CH}_3 \mathrm{Br} \xrightarrow{\mathrm{KcN}} \mathrm{X} \xrightarrow{\mathrm{Na}_2 / \mathrm{C}_2 \mathrm{H}_5 \mathrm{OH}} \mathrm{Y}$$