When hydrochloric acid is added to calcium hydroxide solution, what happens to the pH of the solution?
As you add the acid, the high pH of the calcium hydroxide solution will gradually reduce and then as the volume added approaches the neutralisation point, the pH will drop very rapidly through pH 7 to a much lower value, when it will again start to change more slowly to probably end up close to pH 1. The curve is a familiar stretched “S” shape.
