Identify the major ions present in an aqueous solution of HNO2

In an aqueous solution of HNO2, the major ions present are:

1. H+ ions: These are produced when HNO2, a weak acid, partially ionizes in water.

2. NO2- ions: These are the conjugate base of the acid HNO2. When HNO2 ionizes, it donates a proton (H+) to water, leaving behind NO2- ions.

3. OH- ions: These are produced by the self-ionization of water. Although their concentration is very low compared to H+ and NO2-, they are still present in the solution.

4. H3O+ ions: These are produced when the H+ ions from the ionization of HNO2 combine with water molecules.

So, the major ions present in an aqueous solution of HNO2 are H+, NO2-, OH-, and H3O+.