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 $\mathrm{H}_2 \mathrm{O}$, each oxygen is surrounded by six oxygen in octahedral positions at a distance of $276 \mathrm{pm}$.

Both (i) and (ii) statements are correct. The number of hydrogen bonded water molecules in copper sulphate pentahydrate is one
Water of crystallisation $\left[\mathrm{Cu}\left(\mathrm{H}_2 \mathrm{O}\right)_4\right] \mathrm{SO}_4 \cdot \mathrm{H}_2 \mathrm{O}$ lanthanum and zirconium form non-stoichiometric hydrides. Some hydrides are $\mathrm{LaH}_2, \mathrm{LaH}_3, \mathrm{ZrH}_2$. All hydrides are non-stoichiometric with variable composition, e.g. $\mathrm{ZrH}_x(1.30 \leq x \leq 1.75)$. Most of these hydrides are good conductors of electricity in solid state. In solid form of $\mathrm{H}_2 \mathrm{O}$, each oxygen atom is bonded to four hydrogen atoms, two by hydrogen atoms and two by normal covalent bonds in a near tetrahedral configuration.