Precipitation Reactions happen when anions and cations of aqueous solutions combine to form an insoluble ionic solid, which is also called a precipitate. The determination of whether or not such reactions can happen is done by usage of solubility rules and because all aqueous reactions do not necessarily form precipitates, it is important to go through the rules of solubility before assessing the state of products and analyzing them in order to write a net ionic equation. The ability to predict these reactions accurately allows the scientists to calculate the number of ions which are present in a given solution, ...