Sodium reacts with water to make sodium hydroxide, NaOH\mathrm{NaOH}NaOH, and hydrogen.
What is the balanced symbol equation for this reaction?
Na+H2O→NaOH+H2\mathrm{Na + H_{2}O \rightarrow NaOH + H_{2}}Na+H2O→NaOH+H2
2Na+H2O→2NaOH+H2\mathrm{2Na + H_{2}O \rightarrow 2NaOH + H_{2}}2Na+H2O→2NaOH+H2
2Na+2H2O→2NaOH+H2\mathrm{2Na + 2H_{2}O \rightarrow 2NaOH + H_{2}}2Na+2H2O→2NaOH+H2
Na+H2O→NaOH+H\mathrm{Na + H_{2}O \rightarrow NaOH + H}Na+H2O→NaOH+H
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.