What is the number of moles of $H$ atoms required for the complete reduction of one mole of acetonitrile?

The increasing order of carbon-carbon bond length for the following is:

Predict the product of the following reaction: $CH_2=CH-CH_2-CH_2-COOH \xrightarrow{Br_2, NaHCO_3} \text{Product}$

$2, 4$-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?

Which of the following reactions produce the same product?

What is the major product in the given reaction?