During the electrolysis of dilute sulfuric acid, water is decomposed into hydrogen and oxygen.
Complete the half-equation for the oxidation of hydroxide ions at the positive electrode (anode):
4OH−→2H2O+O2+‾e− 4\text{OH}^- \rightarrow 2\text{H}_2\text{O} + \text{O}_2 + \underline{\quad} \text{e}^- 4OH−→2H2O+O2+e−The overall chemical equation for the electrolysis of water is:
2H2O(l)→2H2(g)+O2(g) 2\text{H}_2\text{O}(\text{l}) \rightarrow 2\text{H}_2(\text{g}) + \text{O}_2(\text{g}) 2H2O(l)→2H2(g)+O2(g)If 56 cm356\text{ cm}^356 cm3 of hydrogen gas is collected at the negative electrode, what volume of oxygen gas is collected at the positive electrode under the same conditions of temperature and pressure?
12 exam-style questions on AQA GCSE Chemistry 4.3 Electrolysis, covering 4.3.1 The process of electrolysis, 4.3.2 Electrolysis of molten ionic compounds, 4.3.3 Using electrolysis to extract metals, 4.3.4 Electrolysis of aqueous solutions, and 4.3.5 Representation of reactions at electrodes as half equations (HT only). Each one has a worked solution and a mark scheme showing where the marks go.