Answer to Question #26289 in Inorganic Chemistry for waqas aijaz

Question

define chemical properties of water?

Answer 1

Chemical properties of water
- has a polar nature
- the molecule of water is a dipole
- can form hydrogen bonds (that's why it has relatively high melting and boiling point temperatures)
- it is a good solvent due to its polarity (ionic and polar substances such as acids, alcohols, and salts are relatively soluble in water, and non-polar substances such as fats and oils are not)
- water is amphoteric: it can be an acid or a base in chemical reactions

When water reacts with an acid, it behaves like a base; when it reacts with the base, it behaves like an acid:

HCl (acid) + H₂O (base) = H₃O⁺ + Cl^−
NH₃ (base) + H₂O (acid) = NH₄⁺ + OH^−

The oxygen atom in water has two lone pairs, that's why water can also be a Lewis base, or electron pair donor, in reactions with Lewis acids:

H⁺ (Lewis acid) + H₂O (Lewis base) = H₃O⁺

Fe³⁺ (Lewis acid) + H₂O (Lewis base) = [Fe(H₂O)₆]³⁺

- When a salt of a weak acid or of a weak base is dissolved in water,
water can hydrolyze the salt:

Na₂CO₃ + H₂O = NaOH + NaHCO₃

- water can be a ligand in transition metal complexes. Typically it's a monodentate ligand, that forms only one bond with the central atom
- Water contains hydrogen in oxidation state +1 and oxygen in oxidation state −2. It can oxidize substances with reduction potential below the potential of H⁺/H₂ (hydrides, alkali and alkaline earth metals). But such as aluminum, are oxidized by water as well, but their oxides are not soluble, and the reaction stops because of passivation.

2Na + 2H₂O = 2NaOH + H₂

- Water also can be oxidized, emitting oxygen gas
4AgF₂ + 2H₂O = 4AgF + 4HF + O₂