How does washing soda help in softening hard water?
Answer and explanation
Correct answer: It helps remove calcium and magnesium ions
Hard water contains dissolved calcium and magnesium salts. Washing soda, sodium carbonate (Na₂CO₃), reacts with these ions and can precipitate them as insoluble carbonates, such as calcium carbonate and magnesium carbonate. Removing these ions reduces hardness, so soap can form lather more easily. It does not acidify water, convert water into hydrogen gas, or destroy soap. Therefore, option A is correct.
Frequently asked questions
What is the correct answer to this question?
It helps remove calcium and magnesium ions
Why is this the correct answer?
Hard water contains dissolved calcium and magnesium salts. Washing soda, sodium carbonate (Na₂CO₃), reacts with these ions and can precipitate them as insoluble carbonates, such as calcium carbonate and magnesium carbonate. Removing these ions reduces hardness, so soap can form lather more easily. It does not acidify water, convert water into hydrogen gas, or destroy soap. Therefore, option A is correct.
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.
