Identify $X$ and $Y$ in the following reaction:
$X \xrightarrow{Y} \text{Benzoquinone}$

In the following Reimer-Tiemann reaction,the product$(s)$ formed is(are):
$p$-cresol + $CHCl_3$ + $OH^-$ $\rightarrow$ ?

Arrange the following compounds in increasing order of $C-OH$ bond length: methanol,phenol,$p-$ethoxyphenol.

The reactivity of compound $Z$ with different halogens under appropriate conditions is given below:
(Image of reaction: $Z$ ($3$-tert-butylphenol) reacts with $X_2$ to give mono-halo derivative for $X_2 = I_2$,di-halo for $X_2 = Br_2$,and tri-halo for $X_2 = Cl_2$)
The observed pattern of electrophilic substitution can be explained by:
$A$. The steric effect of the halogen
$B$. The steric effect of the tert-butyl group
$C$. The electronic effect of the phenolic group
$D$. The electronic effect of the tert-butyl group

Which compound has hydrogen bonding?

When phenol is treated with $D_{2}SO_{4} / D_{2}O$, some of the hydrogens get exchanged. The final product in this exchange reaction is