A student investigated the change in mass when zinc carbonate was heated.
The word equation for the reaction is:
zinc carbonate→zinc oxide+carbon dioxide\text{zinc carbonate} \rightarrow \text{zinc oxide} + \text{carbon dioxide}zinc carbonate→zinc oxide+carbon dioxide
This is the method used:
Table 1 shows the results.
| Total heating time in minutes | Mass of crucible, lid, and contents in grams |
|---|---|
| 0 | 42.65 |
| 2 | 41.85 |
| 4 | 41.33 |
| 6 | 41.33 |
Questions:
Determine the mass of the empty crucible and lid.
Explain why the mass of the crucible, lid, and contents decreased.
Suggest why the crucible, lid, and contents were heated until the mass did not change.
When 125.4 g125.4\text{ g}125.4 g of zinc carbonate is heated until the mass does not change, 118 kJ118\text{ kJ}118 kJ of energy is taken in. The student heated 3.75 g3.75\text{ g}3.75 g of zinc carbonate until the mass did not change. Calculate the energy taken in during this reaction. Give your answer to 3 significant figures.
What type of reaction, in terms of energy transfer, takes place when zinc carbonate is heated?
Practise AQA GCSE Chemistry Chemical measurements, conservation of mass and the quantitative interpretation of chemical equations with exam-style questions for Foundation and Higher tier. 63 questions covering Conservation of mass and balanced chemical equations, Relative formula mass, Mass changes when a reactant or product is a gas, and Chemical measurements, matched to the AQA GCSE Chemistry (8462) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.