everyday science MCQ #476

Permanent hardness of water is due to the presence of:

everyday science MCQ #476

  1. Question 1

    Q1. Permanent hardness of water is due to the presence of:

    • A) Calcium bicarbonate
    • B) Magnesium Bicarbonate
    • C) Calcium sulphate
    • D) Sodium bicarbonate

    Answer: Calcium sulphate

    Explanation: Permanent hardness of water is caused by dissolved calcium sulphate (CaSO₄) and magnesium sulphate (MgSO₄), which cannot be removed by boiling, unlike temporary hardness.