When phenol is treated with $CHCl_3$ and $NaOH$ followed by acidification,salicylaldehyde is produced. Which of the following intermediates is involved in the above reaction?

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

Which of the following reactions will yield $2-propanol$? Select the correct answer from $a, b, c$ and $d$.
$I. \, CH_2 = CH - CH_3 + H_2O \xrightarrow{H^+} $
$II. \, CH_3 - CHO \xrightarrow[(ii) \, H_2O]{(i) \, CH_3MgI} $
$III. \, CH_2O \xrightarrow[(ii) \, H_2O]{(i) \, C_2H_5MgI} $
$IV. \, CH_2 = CH - CH_3 \xrightarrow{KMnO_4} $

Choose the correct option by putting $T$ for the true statement and $F$ for the false statement.
$(i)$ Phenol is more acidic as compared to ethanol.
$(ii)$ Melting point of $o$-nitrophenol is lesser than $p$-nitrophenol.
$(iii)$ Neutralization of phenol is done with $NaHCO_3$.
$(iv)$ Nucleophilic substitution reaction is taking place in the aromatic ring of phenol.

The major products $P$ and $Q$ are

Identify $A$ in the following reaction.