Glycerol $\xrightarrow{KHSO_4} A$ $\xrightarrow{LiAlH_4} B$
$A$ and $B$ are :

The product $P$ is :

Which of the following substances acts as a dehydrating agent for alcohols?

An organic compound $X$ on treatment with $PCC$ in dichloromethane gives the compound $Y$. Compound $Y$ reacts with $I_{2}$ and alkali to form a yellow precipitate of triiodomethane. The compound $X$ is

In the reaction $CH_2OH-CHOH-CH_2OH + COOH-COOH \xrightarrow{110^\circ C} (A)$,product $(A)$ will be:

The number of possible alcoholic isomers for $C_4H_{10}O$ are