What are the concentrations of hydroxide and hydronium ions in a solution with a pH of 4.6? 1.3 * 10-4 M H3O + and 7.7 * 10-11 M OH - 2.5 * 10-5 M H3O + and 4.0 * 10-10 M OH - 7.9 * 10-6 M H3O + and 1.3 * 10-9 M OH - 8.7 * 10-7 M H3O + and 1.1 * 10-8 M OH-

2.5 * 10⁻⁵ M H₃O⁺ and 4.0 * 10⁻¹⁰ M OH⁻.

Explanation:

∵ pH = - log[H₃O⁺]

∴ 4.6 = - log[H₃O⁺].

∴ log[H₃O⁺] = - 4.6.

∴ [H₃O⁺] = 2.51 x 10⁻⁵.

∵ [H₃O⁺][OH⁻] = 10⁻¹⁴.

[H₃O⁺] = 2.51 x 10⁻⁵ M.

∴ [OH⁻] = 10⁻¹⁴/[H₃O⁺] = 10⁻¹⁴ / (2.51 x 10⁻⁵ M) = 3.98 * 10⁻¹⁰ M ≅ 4.0 * 10⁻¹⁰ M.

So, the right choice is: 2.5 * 10⁻⁵ M H₃O⁺ and 4.0 * 10⁻¹⁰ M OH⁻.