Out of the two compounds $A$ ($p$-nitrophenol) and $B$ ($o$-nitrophenol) shown below,the vapour pressure of $B$ at a particular temperature is expected to be:

What is produced when phenol reacts with sodium?

The major product in the following reaction is:

Give the reaction for heating of phenol with zinc powder.

$A$ trisubstituted compound '$A$',$C_{10}H_{12}O_2$ gives a neutral $FeCl_3$ test positive. Treatment of compound '$A$' with $NaOH$ and $CH_3Br$ gives $C_{11}H_{14}O_2$,with hydroiodic acid $(HI)$ gives methyl iodide,and with hot conc. $NaOH$ gives a compound $B$,$C_{10}H_{12}O_2$. Compound '$A$' also decolorises alkaline $KMnO_4$. The number of $\pi$ bonds present in the compound '$A$' is $...........$

Write the chemical equations for the following reactions:
$(i)$ Reimer-Tiemann reaction
$(ii)$ Kolbe's reaction