Ethylene reacts with ozone gas to form the compound

Which products are obtained on reaction of but$-1-$ene with $HBr$ in the presence of peroxide?

The percentage composition of an organic compound $A$ is: carbon = $85.71 \%$ and hydrogen = $14.29 \%$. Its vapour density is $14$. Consider the following reaction sequence:
$A$ $\xrightarrow{Cl_2/H_2O} B$ $\xrightarrow[(ii) H_3O^+]{(i) KCN/EtOH} C$
Identify $C$.

Identify the $(C)$ product of the following reaction:

The addition of $HBr$ to $2-$pentene gives

The product of the following reaction is: