On heating a mixture of $NH_4Cl$ and $KNO_2$,we get:

Complete the following chemical reactions:
$(i) \ PbS_{(s)} + H_2O_{2_{(aq)}} \to $
$(ii) \ MnO_{4_{(aq)}}^{-} + H_2O_{2_{(aq)}} \to $
$(iii) \ CaO_{(s)} + H_2O_{(g)} \to $
$(iv) \ AlCl_{3_{(g)}} + H_2O_{(l)} \to $
$(v) \ Ca_3N_{2_{(s)}} + H_2O_{(l)} \to $
Classify the above into $(a)$ hydrolysis,$(b)$ redox and $(c)$ hydration reactions.

Identify the correct statements from the following:
$i$. Reaction of hydrogen with fluorine occurs even in dark.
$ii$. Manufacture of ammonia by Haber process is an endothermic reaction.
$iii$. $HF$ is an electron-rich hydride.

Among the following reactions of hydrogen with halogens,the one that requires a catalyst is

Which is the lightest gas?

The shape of the colourless neutral gas formed on thermal decomposition of ammonium nitrate is