What is one major use of washing soda?
Answer and explanation
Correct answer: Removing permanent hardness of water
Washing soda is sodium carbonate decahydrate, Na₂CO₃·10H₂O. Carbonate ions react with dissolved calcium and magnesium ions in hard water to form insoluble carbonates, removing them from solution. Thus washing soda softens water and can remove permanent hardness; option A is correct. The other choices describe neither its standard composition nor its principal household use.
Frequently asked questions
What is the correct answer to this question?
Removing permanent hardness of water
Why is this the correct answer?
Washing soda is sodium carbonate decahydrate, Na₂CO₃·10H₂O. Carbonate ions react with dissolved calcium and magnesium ions in hard water to form insoluble carbonates, removing them from solution. Thus washing soda softens water and can remove permanent hardness; option A is correct. The other choices describe neither its standard composition nor its principal household use.
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.
