Which of the following alkenes on ozonolysis gives a mixture of ketones only?

Identify the correct statements with respect to $cis/trans$-but$-2$-ene from the following:
$I$. $cis$-but$-2$-ene is more polar than $trans$-but$-2$-ene
$II$. Melting point of $cis$-but$-2$-ene is greater than that of $trans$-but$-2$-ene
$III$. Boiling point of $cis$-but$-2$-ene is greater than that of $trans$-but$-2$-ene
Correct answer is

Reaction of one molecule of $HBr$ with one molecule of $1,3-$butadiene at $40\,^{\circ}C$ gives predominantly

Pent-$1$-ene reacts with diborane to form $X$. $X$ on oxidation using $H_2O_2$ in the presence of aqueous $NaOH$ gives $Y$. Compound $Y$ is

The metal used for the de-bromination reaction of $1, 2$-dibromoethane is:

What is the product of the reaction: $CH_3-CH=CH_2 \xrightarrow{NOCl}$?