Question

At 25 °C, what is the hydroxide ion concentration, [ OH â ] , in an aqueous solution with a hydrogen ion concentration of [ H + ] = 5.0 à 10 ^â 4 M?

Answer 1

[OH⁻] = 2.0 × 10⁻¹¹ M

Step-by-step explanation:

Given data

• Temperature: 25°C

• Concentration of hydrogen ion ([H⁺]): 5.0 × 10⁻⁴ M

• Concentration of hydroxide ion ([OH⁻]): ?

We can calculate the concentration of hydroxide ion using the following expression.

[H⁺].[OH⁻] = Kw

where,

Kw is the ionic product of water (Kw = 1.0 × 10⁻¹⁴ at 25°C)

[H⁺].[OH⁻] = Kw

[OH⁻] = Kw/[H⁺]

[OH⁻] = 1.0 × 10⁻¹⁴/5.0 × 10⁻⁴

[OH⁻] = 2.0 × 10⁻¹¹ M