Which one of the following is the intermediate in the preparation of a ketone by hydration of an alkyne in the presence of sulfuric acid and mercury $(II)$ sulphate?

The hottest region of the Bunsen flame shown in the figure below is:

For the following compounds,write structural formulas and $IUPAC$ names for all possible isomers having the number of double or triple bonds as indicated:
$(a)$ $C_4H_8$ (one double bond)
$(b)$ $C_5H_8$ (one triple bond)

What is the correct order of acidity for the following hydrocarbons?

The product $(Z)$ is:

For the following reaction scheme,percentage yields are given along the arrows. $x \ g$ and $y \ g$ are the masses of $R$ and $U$,respectively. (Molar mass of $H$,$C$,and $O$ are $1$,$12$,and $16 \ g \ mol^{-1}$ respectively). $(1)$ The value of $x$ is $(2)$ The value of $y$ is.