JEE Main202228 Jul 2022Evening ShiftChemistryHydrogenActual
The products obtained during treatment of hard water using Clark's method are
Options
- ACaCO 3 and MgCO 3
- BCa OH 2 and Mg OH 2
- CCaCO 3 and Mg OH 2
- DCa OH 2 and MgCO 3
Correct answer
C. CaCO 3 and Mg OH 2
Step-by-step solution
In this method calculated amount of lime is added to hard water. It precipitates out calcium carbonate and magnesium hydroxide which can be filtered off In Clark's method lime water is used. It is because of low solubility product of Mg(OH) 2 as compared to that of MgCO 3. Ca HCO 3 2 + 2 Ca OH 2 → 2 CaCO 3 + 2 H 2 O Mg HCO 3 2 + 2 Ca OH 2 → 2 CaCO 3 + Mg OH 2 + 2 H 2 O