Double Replacement Reaction A double replacement reaction is a chemical reaction where two compounds exchange positive ions with each other to form two new compounds . It can be represented by the general chemical equation :
AB + CD → AD + CB
Where A and C are cations and B and D are anions .
Example An example of a double replacement reaction is the reaction between silver nitrate (AgNO3) and sodium chloride (NaCl) to form silver chloride (AgCl) and sodium nitrate (NaNO3):
AgNO3 + NaCl → AgCl + NaNO3
Key Points to Remember Double replacement reactions occur between compounds in aqueous solutions. The cations and anions in the reactants switch partners to form new compounds . Double replacement reactions often result in the formation of a precipitate (solid ) or a gas . The net ionic equation for a double replacement reaction only includes the ions that participate in the reaction. Study Guide When studying double replacement reactions, it's important to understand the following concepts:
Identifying the cations and anions in compounds . Understanding solubility rules to predict whether a precipitate will form in a double replacement reaction. Balancing chemical equations for double replacement reactions. Writing net ionic equations to represent the ions involved in the reaction. .