Write a chemical equation that illustrates the autoionization of water.

The autoionization of water is:

2H₂O ⇄  H₃O⁺  +  OH⁻        Kw

Explanation

2 moles of water can generate hydronium and hydroxide, when they work as an acid or as a base

If we take account that the concentration of protons (hydroniums), at the standard temperature is 1×10⁻⁷ M, it can be considered that the molarity of water is a constant that can be incorporated into a “greater” constant that also includes to Kc and that is known as ionic product of water, Kw. The expression is:

Kw = [H₃O⁺] . [OH⁻] / [H₂O]²

We do not include water → Kw =  [H₃O⁺] . [OH⁻]

Since the water dissociation reaction produces the same concentration of H₃O⁺ as OH⁻, [OH⁻] in pure water will also be 1×10⁻⁷ M

Kw = 1×10⁻⁷ . 1×10⁻⁷ = 1×10⁻¹⁴

pKw = pH + pOH

14 = 7 + 7

the only liquid elements at standard temperature and pressure are bromine (br) and mercury (hg). although, elements caesium (cs), rubidium (rb), francium (fr) and gallium (ga) become liquid at or just above room temperature.

explanation: