NEETChemistryHydrogen
How does washing soda (sodium carbonate) remove permanent hardness from water?
Options
- ABy converting calcium and magnesium ions into sodium ions
- BBy forming soluble carbonates with calcium and magnesium ions
- CBy evaporating the water and leaving behind the hardness ions
- DBy reacting with dissolved gases in the water
Correct answer
B. By forming soluble carbonates with calcium and magnesium ions
Step-by-step solution
Washing soda (sodium carbonate) removes permanent hardness from water by reacting with soluble calcium and magnesium ions to form insoluble carbonates, which can then be precipitated and removed.