ABSTRACT
Iron (III) ions can oxidize iodide ions to iodine. This can be shown as two half equations:
electron loss (oxidation): 2I"(aq) ----> It)(s) + 2e~ The number of electrons gained must equal the number lost. So the first half equation must be doubled to arrive at the overall balanced equation:
half-life (chem ical): the half-life of a chemical reaction is the time for the concentration of one of the reactants to fall by half. Half-lives help to identify firstorder reactions. At a constant temperature, the half-life of a first-order reaction is the same wherever it is measured on a concentration/time graph. So the half-life is independent of the initial concentration.
