Which of the following acids does not produce $H_2$ gas upon reaction with alkali metals?

Which of the following statements about hydrogen is incorrect?

Give uses of Dihydrogen as a fuel.

Identify the correct statements from the following.
$(i)$ The number of hydrogen bonded water molecules in copper sulphate pentahydrate is one.
$(ii)$ Lanthanum and zirconium form non-stoichiometric hydrides.
$(iii)$ In solid form of $H_2O$, each oxygen is surrounded by six oxygen in octahedral positions at a distance of $276 \ pm$.

Which one of the following methyl diboranes does not exist?

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