A student heated 5.00 g5.00\text{ g}5.00 g of zinc carbonate in a crucible to produce solid zinc oxide and carbon dioxide gas.
The reaction is:
zinc carbonate→zinc oxide+carbon dioxide \text{zinc carbonate} \rightarrow \text{zinc oxide} + \text{carbon dioxide} zinc carbonate→zinc oxide+carbon dioxideThe student weighed the crucible and its contents after each minute of heating. The results are shown in the table below:
| Total heating time (minutes) | Mass of crucible and contents (grams) |
|---|---|
| 0 | 23.50 |
| 1 | 22.62 |
| 2 | 22.05 |
| 3 | 21.81 |
| 4 | 21.74 |
| 5 | 21.74 |
Find the minimum heating time needed for all of the zinc carbonate to be completely decomposed.
Calculate the total mass of carbon dioxide gas produced by decomposing the zinc carbonate.
53 exam-style questions on AQA GCSE Chemistry 3.1 Chemical measurements, conservation of mass and the quantitative interpretation of chemical equations, covering 3.1.1 Conservation of mass and balanced chemical equations, 3.1.2 Relative formula mass, 3.1.3 Mass changes when a reactant or product is a gas, and 3.1.4 Chemical measurements. Each one has a worked solution and a mark scheme showing where the marks go.