A manufacturing process deposits a thin coating of one metal, X.
| Coating | Number of atoms of X | Mass of coating in g |
|---|---|---|
| 1 | 1.204 × 1021 | 0.1174 |
| 2 | 3.010 × 1021 | not measured |
| Metal | Relative atomic mass (ArA_rAr) |
|---|---|
| chromium | 52.0 |
| iron | 55.8 |
| nickel | 58.7 |
| copper | 63.5 |
The Avogadro constant is 6.02 × 1023.
Calculate the relative atomic mass of X and hence give the name of metal X.
Show your working.
Calculate the expected mass of coating 2.
Give your answer in g to three significant figures.
134 exam-style questions on OCR GCSE Chemistry 3.1 Introducing chemical reactions, covering 3.1.1 Writing formulae and balanced chemical equations, 3.1.2 Formulae of compounds from ions, and state symbols, 3.1.3 Conservation of mass and observed changes in mass, 3.1.4 Half equations and balanced ionic equations, 3.1.5 The mole and the Avogadro constant, and 3.1.6 Stoichiometry, limiting reactants and reacting masses. Each one has a worked solution and a mark scheme showing where the marks go.