Which of the following statements is correct?
A. The presence of different salts of \(Ca^{2+}, Mg^{2+}\) and \(Fe^{2+}\) in water is termed as hardness of water.
B. Temporary hardness is due to presence of \(Cl^{-}, NO_{3}^{-}, SO_{4}^{2-}\) salts of \(Ca^{2+}, Mg^{2+}\) and \(Fe^{2+}\) in water.
C. Permanent hardness is due to presence of \(HCO_{3}^{-}\) salts of \(Ca^{2+}, Mg^{2+}\) and \(Fe^{2+}\) in water.
D. Both hardness can be removed by simple boiling of water.
সঠিক উত্তরঃ
A.
The presence of different salts of \(Ca^{2+}, Mg^{2+}\) and \(Fe^{2+}\) in water is termed as hardness of water.
