A sealed vessel contains magnesium carbonate and air. When it is heated, all the magnesium carbonate decomposes to form solid magnesium oxide and carbon dioxide gas. The air does not react.
| Substance inside the vessel | Mass before heating in g | Mass after heating in g |
|---|---|---|
| Magnesium carbonate | 4.20 | 0.00 |
| Magnesium oxide | 0.00 | 2.00 |
| Gas | 0.60 | unknown |
Calculate the mass of gas inside the vessel after heating.
95 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.