The reaction of $1,2-$dibromoethane with alcoholic $KOH$ yields product $X$. What is the hybridization of the carbon atoms in $X$?

The reaction $R-C \equiv C-R \xrightarrow{H_2 / \text{Lindlar's catalyst}}$ gives the major product as ..............

$Alkyne \xrightarrow[{Hg^{2+}}]{{H^+/H_2O}} \text{ketone}$
Which of the following alkynes cannot give a ketone?

Consider the following transformations of a compound $P$ $(C_9H_{12})$:
$(i)$ $P \xrightarrow{NaNH_2, C_6H_5COCH_3, H_3O^+/\Delta} R$ (Optically active)
(ii) $P \xrightarrow{Pt/H_2} \text{propylcyclohexane}$
(iii) $P \xrightarrow{X, KMnO_4/H_2SO_4/\Delta} Q$ ($C_8H_{12}O_6$,Optically active acid)
Choose the correct option$(s)$:
$(A)$ $P$ is $3-$cyclohexylprop$-1-$yne
$(B)$ $X$ is $Pd-C/\text{quinoline}/H_2$
$(C)$ $P$ is $1-$cyclohexylprop$-2-$yne
$(D)$ $R$ is $1-$cyclohexyl$-4-$phenylbut$-3-$yn$-2-$ol

When acetylene is passed through a solution of dilute sulfuric acid containing mercuric sulfate,the number of $\pi$ bonds in the final product obtained is.........

In the reaction sequence:
$CH_3-C\equiv CH$ $\xrightarrow{CH_3MgBr}$ $CH_4 + (A)$ $\xrightarrow[ (ii) H_2O/H^{\oplus} ]{(i) CO_2}$ $(B)$
$(B)$ will be: