CHAPTER The Major Classes of Chemical Reactions

Classifying the Countless There are countless chemical reactions txit only a few reaction classes. These swrtng particles of silver chromate form through one of the three major classes discussed in this chapter. 

Many chemical reactions occur in water. Because of the shape of its molecules and ther cfstributton of electrons, water is a po/ar molecule. In water, many ionic compounds and a few simple covalent compounds, such as HCI, cKssociate into ions. 

To describe an aqueous ionic reaction, chemists use a net ionic equation because it eliminates spectator ions (those not involved in the reaction) and shows the actual chemical change taking place. 

Precipitation reactions occur when soluble ionic compounds exchange ions l/netathesis) and form an insoluble product ipredpitate) in which the ions attract each other so strongly that water cannot pull them apart. 

In solution, an acid produces H ions, and a base produces OH ions, in an acid-base (neutraization) reaction, the and the OH ions form water. Another way to view such a reaction is to see an acid as a substance that transfers a proton (H ) to a base. 

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