Ethylene reacts with ozone gas to form the compound

The reaction $CH_2 = CH_2 + H_2 \xrightarrow[{250 - 300 \, ^oC}]{{Ni}} CH_3 - CH_3$ is known as:

Which of the following reagents can be used for the conversion of $1$-Methylcyclopentene to the given product?

In the reaction
$CH_3-CH=CH_2$ $\xrightarrow{Cl_2/500\,^{\circ}C} A$ $\xrightarrow{Na/\text{dry ether}} B$
$B$ is

Which of the following gases decolourises $KMnO_4$ solution but does not give a precipitate with ammoniacal cuprous chloride?

$CH_3-CH=CH_2 \xrightarrow[{(low \, conc.)}]{Br_2/h\nu} (A)$; Product $(A)$ of the reaction is