Question

[H₃O⁺] and [OH⁻] are _______proportional.

a) Directly
b) Inversely
c) Sometimes directly, sometimes inversely
d) None of the above

Answer 1

The concentrations of hydronium ions [H₃O⁺] and hydroxide ions [OH⁻] are inversely proportional to each other, meaning that an increase in one leads to a decrease in the other due to the constant ionic product of water.

Step-by-step explanation:

The concentration of hydronium ions [H₃O⁺] and the concentration of hydroxide ions [OH⁻] are inversely proportional. This means that as the concentration of [H₃O⁺] increases in a solution, the concentration of [OH⁻] decreases, and vice versa. This relationship is due to the constant product of the concentrations of these ions in water at a given temperature, known as the ionic product of water (Kw).

For example, if a solution has a hydronium ion concentration of 2.0 × 10⁻⁶ M at 25 °C, the concentration of hydroxide ion can be found using the ionic product of water at that temperature, which is typically 1.0 × 10⁻¹⁴ M². Using the relationship Kw = [H₃O⁺][OH⁻], we can solve for the unknown concentration of hydroxide ion.