Water can be decomposed into hydrogen and oxygen by of electrolysis.
Complete the half-equation for the production of hydrogen gas at the negative electrode:
2H++‾e−→H2 2\text{H}^+ + \underline{\quad} \text{e}^- \rightarrow \text{H}_2 2H++e−→H2The 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 15 cm3 of oxygen gas is collected, what volume of hydrogen gas is collected 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.