More information on these important concepts is provided in a later chapter on solutions. Substances with relatively low solubilities are said to be insoluble, and these are the substances that readily precipitate from solution. A substance will precipitate when solution conditions are such that its concentration exceeds its solubility. Substances with relatively large solubilities are said to be soluble. The extent to which a substance may be dissolved in water, or any solvent, is quantitatively expressed as its solubility, defined as the maximum concentration of a substance that can be achieved under specified conditions. Precipitation reactions also play a central role in many chemical analysis techniques, including spot tests used to identify metal ions and gravimetric methods for determining the composition of matter (see the last module of this chapter). They are used widely in industry for production of a number of commodity and specialty chemicals. These reactions are common in nature and are responsible for the formation of coral reefs in ocean waters and kidney stones in animals. Many reactions of this type involve the exchange of ions between ionic compounds in aqueous solution and are sometimes referred to as double displacement, double replacement, or metathesis reactions. Precipitation Reactions and Solubility RulesĪ precipitation reaction is one in which dissolved substances react to form one (or more) solid products. This module will provide an introduction to three of the most prevalent types of chemical reactions: precipitation, acid-base, and oxidation-reduction. Faced with a wide range of varied interactions between chemical substances, scientists have likewise found it convenient (or even necessary) to classify chemical interactions by identifying common patterns of reactivity. When they exchange blows with their fists or feet, we say they are fighting. When two humans exchange information, we say they are communicating. Humans interact with one another in various and complex ways, and we classify these interactions according to common patterns of behavior. Compute the oxidation states for elements in compounds.Predict the solubility of common inorganic compounds by using solubility rules.Classify chemical reactions as one of these three types given appropriate descriptions or chemical equations.Define three common types of chemical reactions (precipitation, acid-base, and oxidation-reduction).

By the end of this section, you will be able to:

Precipitate chemistry list