Propyne was subjected to a reaction with $HgSO_4/dil. H_2SO_4$,which resulted in a product $P$. The product $P$ was heated with $Ba(OH)_2$ to give the product $Q$. The molecular formula of the product $Q$ is

The reaction $CH_3CHO \xrightarrow[Zn(Hg) / \text{Conc. } HCl]{[H]} CH_3CH_3$ is:

Hex$-4-$en$-2-$ol on treatment with $PCC$ gives $'A'.$ $'A'$ on reaction with sodium hypoiodite gives $'B',$ which on further heating with soda lime gives $'C'.$ The compound $'C'$ is $....... .$

Which of the following compounds would undergo aldol condensation,which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction.
$(i)$ Methanal $(ii)$ $2-$Methylpentanal $(iii)$ Benzaldehyde $(iv)$ Benzophenone $(v)$ Cyclohexanone $(vi)$ $1-$Phenylpropanone $(vii)$ Phenylacetaldehyde $(viii)$ Butan$-1-$ol $(ix)$ $2,2-$Dimethylbutanal

The reactants $(A)$ and $(B)$ are:

Number of molecules from the following which cannot give the iodoform reaction is $:$ Ethanol,Isopropyl alcohol,Bromoacetone,$2-$Butanol,$2-$Butanone,Butanal,$2-$Pentanone,$3-$Pentanone,Pentanal,and $3-$Pentanol.