Calcium carbide $+ D_2 O \longrightarrow \underline{X} + Ca(OD)_2$.
The hybridisation of carbon atom$(s)$ in $X$ is:

In the following reaction:
$C_2H_2$ $\xrightarrow[HgSO_4 / H_2SO_4]{H_2O} (x)$ $\xrightarrow{\text{Tautomerisation}} CH_3-CHO$
$(x)$ is $:-$

The major product of the following reaction is: $CH_3-CH_2-CH(Br)-CH_2-Br \xrightarrow[(ii) NaNH_2 \text{ in liq. } NH_3]{(i) KOH \text{ alc.}}$

What is Lindlar's catalyst?

$0.40 \, g$ of an organic compound $(A)$ with molecular formula $C_5H_8O$ reacts with $x$ moles of $CH_3MgBr$ to liberate $224 \, mL$ of a gas at $STP$. Upon hydrogenation with excess $H_2$,$(A)$ yields pentan-$1$-ol. The correct structure of $(A)$ is:

The final product of the following reaction is .......
$CaO + 3C$ $\xrightarrow{\text{Heat}} A$ $\xrightarrow{H_2O} B$ $\xrightarrow{H_2SO_4, Hg^{2+}} C$