If the heat of hydrogenation of $1$-butene is $30 \ kcal$,what is the heat of hydrogenation of $1,3$-butadiene (in $kcal$)?

Which one of the following on ozonolysis followed by oxidation will give adipic acid?

$2, 4$-hexadiyne $(CH_3-C\equiv C-C\equiv C-CH_3)$ is allowed to react with $Li$ in $NH_3$ $(liq)$. The product obtained is treated with $1$ equivalent of $Cl_2$ in $CCl_4$. Which of the following constitutional isomers are possible products?

Major product $(A)$ is:

Which of the following reactions results in the formation of a pair of diastereomers?

$CH_2(COOH)_2 \xrightarrow{P_4O_{10}, \, 150^\circ C} X$
Compound $(X)$ is