In which of the following reactions,hydrogen is liberated?
$(i)$ $Al_{(s)} + HCl_{(aq)} \rightarrow$
$(ii)$ $Al_{(s)} + NaOH_{(aq)} \rightarrow$
$(iii)$ $NaBH_4 + I_2 \rightarrow$

The order $H_2O < H_2O_2$ is correct for which of the following properties?

Correct order of boiling point $(BP)$ is:

Match Column-$I$ with Column-$II$ for the given properties/applications mentioned therein.

Column-$I$	Column-$II$
$A$. $H$	$1$. Used in the name of perhydrol.
$B$. $H_2$	$2$. Can be reduced to dihydrogen by $NaH$.
$C$. $H_2O$	$3$. Can be used in hydroformylation of olefin.
$D$. $H_2O_2$	$4$. Can be used in cutting and welding.

Oxalic acid reacts with concentrated $H_2SO_4$ to produce a mixture of two gases. When this mixture is passed through caustic potash,one of the gases is absorbed. Which substance is formed by the absorption of the gas in caustic potash?

Match the following and identify the correct option.

$a. CO_{(g)} + H_{2(g)}$	$i. Mg(HCO_3)_2 + Ca(HCO_3)_2$
$b. \text{Temporary hardness of water}$	$ii. \text{An electron deficient hydride}$
$c. B_2H_6$	$iii. \text{Synthesis gas}$
$d. H_2O_2$	$iv. \text{Non-planar structure}$