pOH is a measure of hydroxide ion (OH^{–}) concentration.

The pOH scale is similar to the pH scale in that a pOH of 7 is indicative of a neutral solution.

pOH is used to express the alkalinity of a solution in where the pH is known.

**Formula to calculate pOH.**

pH is a scale used to specify the acidity or basicity of an aqueous solution.

**Example:**

Find the pOH of a substance whose pH is 3.

Therefore, the pOH of the substance is 11.