Which of the following facts are the evidence for the ionic nature of $LiH$?

Pick the odd one out regarding the properties of sodium borohydride $(NaBH_4)$.

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.

Given below are two statements,one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A:$ Isotopes of hydrogen have almost same chemical properties,but difference in their rates of reaction.
Reason $R:$ Isotopes of hydrogen have different enthalpy of bond dissociation.
In the light of the above statements,choose the most appropriate answer from the options given below:

Identify the correct composition of water gas from the following.

Atoms in hydrogen gas have a preponderance of which isotope?