AP Chemistry/Reactions

Reactants form products. Reactions may be exothermic (releasing heat) or endothermic (absorbing heat). Types of Reactions Synthesis: A + B → AB Decomposition: AB → A + B Single Replacement: AB + C → AC + B. Double Replacement: AB + CD → AD + CB. Precipitation - when two ionic compounds are dissolved in a solvent, they form four ions. Quite often, the positive ion from one compound will react with the negative ion from the other, forming an insoluble compound. This compound precipitates to the bottom as a solid. Neutralization - when an acid and base are mixed, water and a salt will form. Redox Reactions These are reactions where the oxidation numbers of particles change. The particle whose oxidation number decreases is reduced, and is called an oxidizing agent. The other particle is oxidized, and is called a reducing agent. If oxygen is the oxidizing agent, the reaction is called combustion. Predicting Chemical Reactions Kinetics Rate constant - constant only for a specific reaction and temperature. Order of a reaction - add up all the exponents of the molarities.