Total number of possible isomers (both structural as well as stereoisomers) of cyclic ethers with the molecular formula $C_4H_8O$ is:

Arrange the following sets of compounds in order of their increasing boiling points:
$(a)$ Pentan$-1-$ol,butan$-1-$ol,butan$-2-$ol,ethanol,propan$-1-$ol,methanol.
$(b)$ Pentan$-1-$ol,$n-$butane,pentanal,ethoxyethane.

Match the compounds in Column-$I$ with their $C-O$ bond length in Column-$II$ and $C-O-H$ bond angle in Column-$III$.

Column-$I$ (Name)	Column-$II$ ($C-O$ bond length) and Column-$III$ ($C-O-H$ angle)
$A$. Methanol	$1$. $141 \ pm$,$i$. $109^o$
$B$. Phenol	$2$. $136 \ pm$,$ii$. $111.7^o$
$C$. Methoxymethane	$3$. $142 \ pm$,$iii$. $108.9^o$

The correct match about the reaction sequence shown above is:

Match the reactions in Column $(I)$ with the products formed in Column $(II)$.

Column $(I)$	Column $(II)$
$(A)$ Kolbe's reaction	$(i)$ Salicylaldehyde
$(B)$ Reimer-Tiemann reaction	$(ii)$ Ethers
$(C)$ Williamson synthesis	$(iii)$ Ethanol
$(D)$ Fermentation	$(iv)$ Salicylic acid

Which of the following statements are correct for phenol?
$(A)$ In general,phenol is more acidic than alcohol.
$(B)$ Phenol is used in the production of melamine plastic.
$(C)$ Phenol gives violet colour with neutral ferric chloride solution.
$(D)$ Phenol when heated with acetyl chloride gives phenetole.