$X$ (Symmetrical alkyne) $\xrightarrow{Hg^{2+}/H_3O^{+}}$ $2-$butanone. Which compound reacts with $Ag$ powder to give $X$?

Identify $Z$ in the following sequence:
${C_3}{H_7}OH$ $\xrightarrow{conc. \ H_2SO_4} X$ $\xrightarrow{Br_2} Y$ $\xrightarrow[alc. \ KOH]{high \ level} Z$

One mole of $1,2$-dibromopropane on treatment with $X$ moles of $NaNH_2$ followed by treatment with ethyl bromide gave a pentyne. The value of $X$ is

Compound $(X)$ [styrene] is subjected to the following sequence of reactions: $(i)$ $Br_2/CHCl_3$,$(ii)$ $NaNH_2$ (excess),$(iii)$ $CH_3I$,$(iv)$ $H_2, Na/NH_3(l)$,giving Major Product $(Y)$. The molar mass of the major product $(Y)$ formed is . . . . . . $\text{g mol}^{-1}$. (Given molar mass in $\text{g mol}^{-1}$: $C:12, H:1$)

Which alkyne yields butanoic acid $(CH_3CH_2CH_2CO_2H)$ as the only organic product on treatment with ozone followed by the hydrolysis?

Which one of the following is more acidic?