Rank the solutions in order of decreasing [H3O ]. Rank solutions from largest to smallest hydronium ion concentration. To rank items as equivalent, overlap them. a. 0.10 M HNO3.
b. 0.10 M HCN.
c. 0.10 M HNO2.
d. 0.10 M HClO. e. smallest concentration. f. largest concentration.

0.10M HCN  <  0.10 M HClO  <  0.10 M HNO₂  < 0.10 M HNO₃

Explanation:

We are comparing acids with the same concentration. So what we have to do first is to determine if we have any strong acid and for the rest ( weak acids ) compare them by their Ka´s ( look for them in reference tables ) since we know the larger the Ka, the more Hydronium concentration will be in these solutions at the same concentration.

HNO₃ is a strong acid and will have the largest hydronium concentration.

HCN  Ka = 6.2 x 10⁻¹⁰

HNO₂ Ka = 4.0 x 10⁻⁴

HClO  Ka = 3.0 x 10⁻⁸

The ranking from smallest to largest hydronium concentration will then be:

0.10M HCN  <  0.10 M HClO  <  0.10 M HNO₂  < 0.10 M HNO₃