Question

Calculate the [OH−] [H3O+]=3.0×10−9M

Answer 1

Thus the value of [OH⁻] calculated is = 3.3 × 10⁻⁶ M

Explanation:

Given:

Concentration of H₃O⁺ = 3.3 × 10⁻⁹ M

To Find:

Concentration of OH⁻ ion = ?

Solution:

From the $K_{w}$ value, and the concentration of H⁺ ion, we can find the concentration of hydroxyl ions, as $K_{w}$ is the product of the concentration of H⁺ and OH⁻ ions. We have the concentration of hydronium ion or H⁺ ion and $K_{w}$ value, dividing $K_{w}$ by the H⁺ ion concentration, we will get the concentration of OH⁻ ion as,

$K_{w}$ = [H₃O⁺] × [OH⁻]

    = 3.0 × 10⁻⁹ × [OH⁻]

Now we have to divide as,

[OH⁻] =  $\frac{1\times10^-14}{3\times10^{-9}}$ = 3.3 × 10⁻⁶ M