When calcium carbonate is heated in an intact closed container, it decomposes into calcium oxide and carbon dioxide. If the carbon dioxide does not escape, what can be concluded about the total mass of the container and its contents before and after the reaction?
Answer and explanation
Correct answer: The total mass will remain unchanged
The reaction is \(\mathrm{CaCO_3(s) \rightarrow CaO(s) + CO_2(g)}\). In an intact closed container, no matter, including \(\mathrm{CO_2}\), leaves the system, so the total mass of the container and all its contents remains unchanged. Option B could apply to an open container, where escaping \(\mathrm{CO_2}\) can make the measured mass decrease.
Frequently asked questions
What is the correct answer to this question?
The total mass will remain unchanged
Why is this the correct answer?
The reaction is \(\mathrm{CaCO_3(s) \rightarrow CaO(s) + CO_2(g)}\). In an intact closed container, no matter, including \(\mathrm{CO_2}\), leaves the system, so the total mass of the container and all its contents remains unchanged. Option B could apply to an open container, where escaping \(\mathrm{CO_2}\) can make the measured mass decrease.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Chemical Reactions and Equations.
