Assertion (A): Hardness of water is removed by treatment with sodium carbonate.
Reason (R): Sodium carbonate reacts with soluble magnesium and calcium chloride to form water soluble compounds.
A
(A) and (R) both are correct and (R) is the correct explanation of (A).
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
(A) and (R) both are correct but (R) is not the correct explanation of (A).
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
(A) is correct but (R) is not correct.
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
(A) is not correct but (R) is correct.
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is C (A) is correct but (R) is not correct. Hardness of water is due to the presence of chlorides and sulphates of calcium and magnesium. It can be removed by adding sodium carbonate (Na2CO3).
Hard water forms insoluble compound (either calcium carbonate or magnesium carbonate) on reaction with sodium carbonate. This insoluble compound is later filtered out. The reaction involved is:
CaCl2(aq)+Na2CO3(s)→CaCO3(s)+NaCl(aq)
Hence, the assertion is correct but the reason is not correct.