Skip to content

Course home

3.3 Yield and atom economy of chemical reactions

3.3 Yield and atom economy of chemical reactions

EasyMedium
123456789101112131415161718
Question 3

This question is about the extraction of metals.

Element Y is extracted from its oxide by reduction with carbon. The equation for the reaction is:

YO2+C→Y+CO2 \text{YO}_2 + \text{C} \rightarrow \text{Y} + \text{CO}_2 YO2​+C→Y+CO2​
a.

The sum of the relative formula masses (MrM_rMr​) of the reactants (YO2+C\text{YO}_2 + \text{C}YO2​+C) is 99. Calculate the relative atomic mass (ArA_rAr​) of Y. Relative atomic masses (ArA_rAr​): C=12\text{C} = 12C=12, O=16\text{O} = 16O=16

[2]
b.

Identify element Y using your answer to Part 1 and a periodic table.

[1]
c.

Carbon can also be used to extract iron (Fe\text{Fe}Fe) from iron(III) oxide (Fe2O3\text{Fe}_2\text{O}_3Fe2​O3​). The equation for the overall reaction is:

Fe2O3+3C→2Fe+3CO \text{Fe}_2\text{O}_3 + 3\text{C} \rightarrow 2\text{Fe} + 3\text{CO} Fe2​O3​+3C→2Fe+3CO

Calculate the percentage atom economy for extracting iron in this reaction. Give your answer to 2 significant figures. Relative atomic masses (ArA_rAr​): C=12\text{C} = 12C=12, O=16\text{O} = 16O=16, Fe=56\text{Fe} = 56Fe=56

[4]
Markscheme

3.3 Yield and atom economy of chemical reactions Questions

  1. GCSE
  2. /Chemistry
  3. /3.3 Yield and atom economy of chemical reactions

31 exam-style questions on AQA GCSE Chemistry 3.3 Yield and atom economy of chemical reactions, covering 3.3.1 Percentage yield and 3.3.2 Atom economy. Each one has a worked solution and a mark scheme showing where the marks go.

Question bank