A student investigated the change in mass when hydrated nickel sulfate was heated.
The word equation for the reaction is:
hydrated nickel sulfate⇌anhydrous nickel sulfate+water \text{hydrated nickel sulfate} \rightleftharpoons \text{anhydrous nickel sulfate} + \text{water} hydrated nickel sulfate⇌anhydrous nickel sulfate+waterThis is the method used:
The table below shows the results.
| Total heating time in minutes | Mass of crucible and contents in grams |
|---|---|
| 0 | 26.50 |
| 1 | 24.85 |
| 2 | 24.30 |
| 3 | 24.30 |
Determine the mass of the empty crucible.
Explain why the mass of the crucible and contents decreased.
Suggest why the crucible and contents were heated until the mass did not change.
When 200 g200\text{ g}200 g of hydrated nickel sulfate is heated until the mass does not change, 68.4 kJ68.4\text{ kJ}68.4 kJ of energy is taken in. The student heated 4.20 g4.20\text{ g}4.20 g of hydrated nickel sulfate 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 takes place when hydrated nickel sulfate is heated?
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.