Final product formed on reduction of glycerol by hydroiodic acid is

The major product of the following reaction is

In the given selective hydrogenation,which combination is incorrect?

What product is formed when the alkene $R-CH=CH_2$ reacts with $B_2H_6$ in the presence of $H_2O_2$?

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

$H_2O_2$ on reacting with ethene gives: