Iron reacts with chlorine gas to make iron(III) chloride, FeCl₃.
A student heats 2.79 g of iron wool in a stream of chlorine gas until all of the iron has reacted.
The mass of iron(III) chloride made is 8.12 g.
Relative atomic mass (Ar): Cl = 35.5, Fe = 55.8
Calculate the mass of chlorine that reacted with the iron.
Mass of chlorine = ...... g
Use the masses to deduce the balanced symbol equation for the reaction.
Show your working.
In a second experiment, the student reacts 5.58 g of iron with 7.10 g of chlorine.
Determine which reactant is the limiting reactant and calculate the maximum mass of iron(III) chloride that can be made.
Give your answer to 3 significant figures.
Maximum mass of iron(III) chloride = ...... g
The student adds more iron to the second experiment but uses the same mass of chlorine.
Explain why the maximum mass of iron(III) chloride does not increase.
55 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.