4.80 g of magnesium was burned in an excess of oxygen. 6.40 g of magnesium oxide was made.
2Mg+O2→2MgO2\text{Mg} + \text{O}_2 \rightarrow 2\text{MgO}2Mg+O2→2MgO
Relative atomic masses: O=16\text{O} = 16O=16, Mg=24\text{Mg} = 24Mg=24.
What is the percentage yield of magnesium oxide?
57.1 %57.1\ \%57.1 %
66.7 %66.7\ \%66.7 %
75.0 %75.0\ \%75.0 %
80.0 %80.0\ \%80.0 %
39 exam-style questions on AQA GCSE Chemistry 3.3 Yield and atom economy of chemical reactions, covering 3.3.1a Percentage yield, 3.3.1b Theoretical mass of a product, 3.3.2a Atom economy, and 3.3.2b Choosing a reaction pathway. Each one has a worked solution and a mark scheme showing where the marks go.