How does washing soda soften hard water?
Answer and explanation
Correct answer: By removing calcium and magnesium ions
Hard water contains dissolved calcium and magnesium ions, which can form deposits and react with soap. Washing soda supplies carbonate ions that precipitate these ions as insoluble carbonates, such as calcium carbonate and magnesium carbonate. Removing them reduces hardness, so option A is correct. The process does not depend on hydrogen or chlorine gas and does not make the water acidic.
Frequently asked questions
What is the correct answer to this question?
By removing calcium and magnesium ions
Why is this the correct answer?
Hard water contains dissolved calcium and magnesium ions, which can form deposits and react with soap. Washing soda supplies carbonate ions that precipitate these ions as insoluble carbonates, such as calcium carbonate and magnesium carbonate. Removing them reduces hardness, so option A is correct. The process does not depend on hydrogen or chlorine gas and does not make the water acidic.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Acids, Bases, and Salts.
