The compound obtained by heating salicylic acid with phenol in the presence of phosphorus oxychloride $(POCl_3)$ is

In the given reaction sequence,identify the final product $B$:
Phenol $\xrightarrow[(2) CO_2]{(1) OH^-} A$ $\xrightarrow[Pyridine]{CH_3COCl} B$

Describe the reactions of nitration and bromination of phenol.

Two aromatic compounds having formula $C_7H_8O$ which are easily identifiable by $FeCl_3$ solution test (violet colouration) are

The Reimer-Tiemann reaction introduces an aldehyde group onto the aromatic ring of phenol,ortho to the hydroxyl group. This reaction involves electrophilic aromatic substitution. This is a general method for the synthesis of substituted salicylaldehydes as depicted below.
$1.$ Which one of the following reagents is used in the above reaction?
$A.$ aq. $NaOH + CH_3Cl$
$B.$ aq. $NaOH + CH_2Cl_2$
$C.$ aq. $NaOH + CHCl_3$
$D.$ aq. $NaOH + CCl_4$
$2.$ The electrophile in this reaction is
$A.$ $:CHCl$
$B.$ $^{+}CHCl_2$
$C.$ $:CCl_2$
$D.$ $CCl_3^{-}$
$3.$ The structure of the intermediate $I$ is
(See provided image for structures $A$,$B$,$C$,$D$)
Give the answer for questions $1, 2$ and $3.$

The reaction which involves dichlorocarbene as an electrophile is,