A commemorative coin minted to celebrate a royal jubilee has a total mass of 16.0 g. Chemical analysis of the alloy reveals that it contains 14.0 g of pure gold, with the remainder being copper and silver to increase its wear resistance.
Using the table below, determine the purity of this gold coin in carats.
| Percentage of gold in the alloy (%) | Purity of gold in carats |
|---|---|
| 37.5 | 9 |
| 50.0 | 12 |
| 62.5 | 15 |
| 75.0 | 18 |
| 87.5 | 21 |
| 100.0 | 24 |
Show your working.
97 exam-style questions on Edexcel GCSE Chemistry 6.1 Transition metals, alloys and corrosion, covering 6.1.1 Properties of transition metals, 6.1.2 Corrosion and its prevention, and 6.1.3 Alloys and the uses of metals. Each one has a worked solution and a mark scheme showing where the marks go.