How will the gas formed on heating baking soda be confirmed?
Answer and explanation
Correct answer: By lime water turning milky
The governing concept is the thermal decomposition of sodium hydrogen carbonate. On heating, baking soda decomposes as 2NaHCO3 → Na2CO3 + H2O + CO2. The released carbon dioxide is passed through limewater, where it reacts with calcium hydroxide to form insoluble calcium carbonate, making the limewater milky. Hence option A is correct. A pop sound tests hydrogen, while the other indicators do not specifically confirm carbon dioxide.
Frequently asked questions
What is the correct answer to this question?
By lime water turning milky
Why is this the correct answer?
The governing concept is the thermal decomposition of sodium hydrogen carbonate. On heating, baking soda decomposes as 2NaHCO3 → Na2CO3 + H2O + CO2. The released carbon dioxide is passed through limewater, where it reacts with calcium hydroxide to form insoluble calcium carbonate, making the limewater milky. Hence option A is correct. A pop sound tests hydrogen, while the other indicators do not specifically confirm carbon dioxide.
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.
