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3.1 Introducing chemical reactions

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Question 10

To prepare sodium oxide, sodium is burned in a measured supply of oxygen. In a trial, 9.2 g of sodium and 3.2 g of oxygen are both fully consumed.

4Na+O2→2Na2O \mathrm{4Na + O_2 \rightarrow 2Na_2O} 4Na+O2​→2Na2​O

What mass of sodium is needed to use up 8.0 g of oxygen completely?

[1]
A

3.7 g

B

9.2 g

C

32.0 g

D

23.0 g

Markscheme

3.1 Introducing chemical reactions Questions

  1. GCSE
  2. /Chemistry
  3. /3.1 Introducing chemical reactions

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.

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