The pH of a solution is determined on a scale from 0 to 14. Pure water has a pH of 7, which means it is neutral. A pH of less than 7 means the solution is acidic, and greater than 7 means it is basic.

Sodium hydroxide (NaOH) is a strong base, meaning it dissociates completely in water to form hydroxide ions (OH-). This makes NaOH solutions very basic. The pH of a 1M solution of sodium hydroxide is approximately 14.