Question

What is the concentration of hydroxide ions in pure water at 30.0 ∘C, of Kw at this temperature is 1.47x10-14?

Answer 1

Answer:

[OH⁻] = 1.21×10⁻⁷

Explanation:

Water dissociates in the solution as:

H₂O ⇔ H⁺ + OH⁻

For pure water, the concentration of [H⁺] and [OH⁻] are equal.

Kw is defined as the product of the active concentration of  H⁺ and OH⁻ furnished by the water.

So,

Kw = [H⁺] [OH⁻]

Given that, at 30.0 °C, the Kw is 1.47×10⁻¹⁴

So,

Kw = [H⁺] [OH⁻]

As stated above, [H⁺] = [OH⁻]

1.47×10⁻¹⁴ = [OH⁻]²

[OH⁻] = 1.21×10⁻⁷