Synthesis: When multiple reactants combine to form a single product. (Ex. Hydrogen reacts with oxygen to form water.)
Decomposition: When a single compound breaks down into two or more elements to form new compounds. (Ex. Source such as heat can break apart compounds; water breaks down most ionic compounds.)
Single- Replacement: When an element or ion moves out of one compound and into another.
Double- Replacement: When one positive ion is exchanged with another positive ion.
Neutralization: When an acid and base react to form water and salt.
Combustion: When two reactants combine to form one product.