Which of the following reagents will produce salicylaldehyde on reaction with phenol?

Match the following acids with their respective $pK_a$ values:

Acid	$pK_a$
$(i)$ Phenol	$a. 10$
$(ii)$ $p-$Nitrophenol	$b. 7.1$
$(iii)$ Ethyl alcohol	$c. 16$
$(iv)$ Picric acid	$d. 0.78$

Give the reaction for heating of phenol with zinc powder.

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 are $X$ and $Y$ respectively in the following set of reactions?

What is the increasing order of acidic strength among the following?
$(i)$ $p-$methoxy phenol
$(ii)$ $p-$methyl phenol
$(iii)$ $p-$nitro phenol