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3.3 Yield and atom economy of chemical reactions

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Question 9
H

Aluminium is extracted from aluminium oxide by electrolysis.

2Al2O3→4Al+3O22\text{Al}_2\text{O}_3 \rightarrow 4\text{Al} + 3\text{O}_22Al2​O3​→4Al+3O2​

A factory electrolyses 8.00 kg of aluminium oxide and obtains 3.60 kg of aluminium.

Relative atomic masses: O=16\text{O} = 16O=16, Al=27\text{Al} = 27Al=27.

a.

Calculate the maximum theoretical mass of aluminium, in kg\text{kg}kg, that could be obtained from 8.00 kg of aluminium oxide.

[3]
b.

Calculate the percentage yield of aluminium. Give your answer to 3 significant figures.

[2]
c.

Give one reason why the percentage yield of aluminium is less than 100 %.

[1]
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

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.

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