Question

The hardness of water is estimated by

• A. EDTA method
• B. titrimetric method
• C. conductivity method
• D. distillation method

Answer 1

Answer: (A)

The hard water contains soluble salts of calcium or magnesium. Therefore, the hardness of water is estimated by EDTA method.
EDTA (ethylene diamine tetracetic acid) is a white crystalline powder. It is used as a titrant for the volumetric estimation of calcium, magnesium and other metals. EDTA when treated with water forms stable complex with metal ions. Note