What is the pH of a 0.1 M solution of NaOH?

To determine the pH of a 0.1 M solution of NaOH, we first recognize that NaOH is a strong base that completely dissociates in water. When dissolved, NaOH will dissociate into sodium ions (Na⁺) and hydroxide ions (OH⁻). For every mole of NaOH that dissolves, it produces one mole of OH⁻.

In a 0.1 M NaOH solution, the concentration of hydroxide ions is also 0.1 M. To find the pOH, we can use the formula:

pOH = -log[OH⁻]

Substituting the concentration of OH⁻ into the formula gives:

pOH = -log(0.1) = 1.

Since pH and pOH are related by the equation:

pH + pOH = 14,

we can calculate the pH:

pH = 14 - pOH = 14 - 1 = 13.

Therefore, the pH of a 0.1 M NaOH solution is indeed 13. This is characteristic of strong bases, where a strong base like NaOH significantly increases the pH due to the high concentration of hydroxide ions produced,