Which pair is not correct?
Answer and explanation
Correct answer: Bleaching powder — Sodium chloride
The governing concept is the identification and composition of common salts. Baking soda is sodium hydrogen carbonate, NaHCO₃. Washing soda is sodium carbonate decahydrate, Na₂CO₃·10H₂O. Plaster of Paris is calcium sulphate hemihydrate, CaSO₄·½H₂O. Bleaching powder is a chlorine-containing bleaching compound commonly represented at school level as CaOCl₂; it is not sodium chloride, NaCl, which is common salt. Therefore option D is the incorrect pair.
Frequently asked questions
What is the correct answer to this question?
Bleaching powder — Sodium chloride
Why is this the correct answer?
The governing concept is the identification and composition of common salts. Baking soda is sodium hydrogen carbonate, NaHCO₃. Washing soda is sodium carbonate decahydrate, Na₂CO₃·10H₂O. Plaster of Paris is calcium sulphate hemihydrate, CaSO₄·½H₂O. Bleaching powder is a chlorine-containing bleaching compound commonly represented at school level as CaOCl₂; it is not sodium chloride, NaCl, which is common salt. Therefore option D is the incorrect pair.
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.
