How does the overall redox potential show that the reaction occurring is spontaneous?
A redox reaction can be considered as two half reactions. You can predict the expected direction of change for a redox reaction by considering the electrode potentials for the two half equations. One way of doing this is to write down the conventional cell diagram and work out the overall cell emf. The agreed convention is that the sign of the cell emf is the charge on the right-hand electrode. If the cell emf is positive the reaction tends to go according to the cell diagram read from left to right. That is the direction of spontaneous change. Don’t forget that a reaction may tend to go (be spontaneous) but nevertheless be exceedingly slow. Risk assessment Before attempting any practical work based on the advice and suggestions on this website, you must do the following. Identify any hazards, assess the risks from these hazards, and then decide appropriate control measures to reduce the risks. You must have these approved by those in authority in your school or college laboratory. Do
