A key part of the assessment of this unit is to carry out some experiments and infer what is happening. We then need to write balanced half-equations and overall equations, as well as identifying what is acting as the oxidant and what is the reductant.
Some ions are very difficult to identify due to their colours. For example, both Fe3+ and Cr2O72- are orange; Fe2+ is such a pale green that it often looks colourless. We need to use some other reagents/tests to confirm what has been produced: