MHT CET202613 April 2026Evening ShiftChemistryHydrogenActual
Which of the following ions are responsible for hardness of water?
Options
- AAg ^+, Au ³⁺ ions
- BHg ²⁺, Pb ²⁺ ions
- CCa ²⁺ and Mg ²⁺ ions.
- DAs ³⁺, CN ^-
Correct answer
C. Ca ²⁺ and Mg ²⁺ ions.
Step-by-step solution
Hardness of water is primarily caused by the presence of soluble salts of calcium and magnesium, such as their bicarbonates, chlorides, and sulfates. Therefore, Ca ²⁺ and Mg ²⁺ ions are responsible for the hardness of water. Answer: Ca ²⁺ and Mg ²⁺ ions.