Which of the following is not a common use of gypsum? a. wallboard/drywall for homes b. a primary ingredient for toothpaste c. surgical splints and casts d. pH reducing agent for acidic soils

pH reducing agent for acidic soils

Explanation:

Gypsum is not used to reduce soil pH because it will displace the soil H + but there's no means of extracting the H from the soil. So the pH of the soil remains the same.