Identify the catalyst used in the following reaction: $CO_{(g)} + H_2O_{(g)} \xrightarrow{623 \ K} CO_{2_{(g)}} + H_{2_{(g)}}$

The correct statements among $(a)$ to $(d)$ regarding $H_2$ as a fuel are:
$(a)$ It produces fewer pollutants than petrol.
$(b)$ $A$ cylinder of compressed dihydrogen weighs $\sim 30$ times more than a petrol tank producing the same amount of energy.
$(c)$ Dihydrogen is stored in tanks of metal alloys like $NaNi_5$.
$(d)$ On combustion,the values of energy released per gram of liquid dihydrogen and $LPG$ are $142$ and $50 \ kJ,$ respectively.

In the reaction:
$2x + B_2H_6 \longrightarrow [BH_2(x)_2]^+ [BH_4]^-$
the amine $x$ will not be:

Dehydration of oxalic acid with concentrated $H_2SO_4$ produces ............

Elements of which of the following group$(s)$ of the periodic table do not form hydrides?

Which of the following has the highest calorific value?