Chapter 5 Section 2 Notes

Reaction Types

Synthesis Reaction

• Synthesis Reaction: a reaction in which at least 2 substances make a new, more complex compound.

• General Form: A + B → AB

• Example: 2Na + Cl2 → 2NaCl

Synthesis Reaction

Decomposition Reaction

• Decomposition Reaction: a reaction in which one compound breaks into at least 2 parts

• General Form: AB → A + B

• Example: 2H2O → 2H2 + 02

• Electrolysis: the decomposition of a compound by electric current.

Decomposition Reaction

Combustion Reaction

• Combustion Reaction: a reaction in which a compound and oxygen burn.

• Note: carbon containing compound & oxygen are always reactants and carbon dioxide & water are always products.

• If the air supply is limited when carbon-containing fuel burns, there might not be enough oxygen gas for all of the carbon to form carbon dioxide. In that case, carbon monoxide may form. Carbon monoxide is dangerous because it has no color or odor and you can’t tell when it’s present.

Combustion Reaction

Single-Displacement Reaction

• Single-Displacement Reaction: A reaction in which the atoms of one element take the place of atoms of another element in a compound.

• General Form: XA + B → BA + X

Single-Displacement Reaction

• Note: Generally, a more reactive element will take the place of a less reactive one.

• Example: 3CuCl2 + 2Al → 2AlCl3 + 3Cu

Single-Displacement Reaction

Double-Displacement Reaction• Double-Displacement reaction: a

reaction in which a new substance is made by the exchange of ions between 2 compounds.

• General Form: AX + BY → AY + BX

• Example: Pb(NO3)2 + K2CrO4 → PbCrO4 + 2KNO3

Double-Displacement Reaction