On an industrial scale, hydrogen peroxide is prepared by auto oxidation of 2-alkyl  anthraquinol.

Copper sulphate pentahydrate CuSO₄.5H₂O. In this compound, 4 water molecules form coordinate bonds while the fifth water molecule present outside the coordination can form intermolecular hydrogen bond with another molecule as [CU(H₂O)₄]SO₄.H₂O.

(i) Water reacts with SiCl₄ to give silica.
SiCl₄ + 4H₂O ⟶ Si(OH)₄ + 4HCI
Si(OH)₄ \(\overset { \Delta }{ \longrightarrow } \) SiO₂ + 2H₂O
Silica
(ii) Water reacts with P4010 to give orthophosphoric acid.
P₄O₁₀ + 6H₂O ⟶ 4H₃PO₄
Orthophosphoric acid

Hydrogen has a tendency to react with reactive metals like lithium, sodium to give corresponding hydrides.
2 Li + H₂ ⟶ 2 LiH
2 Na + H₂ ⟶  2 NaH
These hydrides are used as reducing agents in synthetic organic chemistry. It is also used to prepare important hydrides such as lithium aluminium hydride and sodium boro hydride (organic reducing agents).
4 LiH + AICl₃   ⟶ Li[AlH₄] + 3 LiCI
4 NaH + B(OCH₃)₃ ⟶ Na[BH₄] + 3CH₃ONa

(i) Hydrogen sponge (or) Metal hydride e.g., palladium-hydrogen system is a binary hydride (PdH).
(ii) Upon heating, H atoms diffuse through the metal to the surface and recombine to form molecular hydrogen. Since no other gas behaves this way with palladium, this process has been used to separate hydrogen gas from other gases:
2 Pd_(s) + H_2(g) \(\rightleftharpoons \) 2PdH_(s)
(iii) The hydrogen molecule readily adsorb on the palladium surface, where it dissociates into atomic hydrogen. The dissociated atoms dissolve into the interstices or voids (octahedral or tetrahedral) of the crystal lattice.

(iv) Technically, the formation of metal hydride is by chemical reaction but it behaves like a physical storage method, i.e., it is absorbed and released like a water sponge. Such a reversible uptake of hydrogen in metals and alloys is also attractive for hydrogen storage and for rechargeable metal hydride battery applications.