Final answer:
A double-replacement reaction is a chemical reaction in which parts of two ionic compounds are exchanged, forming two new compounds. The reaction occurs in aqueous solution and typically involves the formation of a solid precipitate, a gas, or a molecular compound.
Step-by-step explanation:
A double-replacement reaction is a chemical reaction in which parts of two ionic compounds are exchanged. The reaction occurs between substances in aqueous solution and results in the formation of two new compounds. In order for a reaction to occur, one of the products is usually a solid precipitate, a gas, or a molecular compound such as water.
An example of a double-replacement reaction is when the reactants AB and CD combine to form the products AD and CB:
AB + CD → AD + CB