Acids and bases a solvent-oriented definition

A Br0nsted acid is a proton donor, and a Bronsted base accepts protons. In aqueous solution, [H30] is formed and in bulk water, self-ionization corresponds to the transfer of a proton from one solvent molecule to another (equation 9.11) illustrating amphoteric behaviour (see Section 7.8). 

In hquid NH3 (see Section 9.6), proton transfer leads to the formation of [NH4]+ (equation 9.12), and, in a liquid ammonia solution, an add may be described as a substance that produces [NH4] ions, while a base produces [NH2] ions. 

This solvent-oriented definition can be widened to include behaviour in any solvent which undergoes self-ionization. 

In a self-ionizing solvent, an acid is a substance that produces the cation characteristic of the solvent, and a base is a substance that produces the anion characteristic of the solvent. 

Liquid dinitrogen tetraoxide, N2O4, undergoes the selfionization shown in equation 9.13. In this medium, nitrosyl salts such as [N0][C104] behave as adds, and metal nitrates (e.g. NaN03) behave as bases. 

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