Chemical Equations and other fun with chemistry.

Parts of a chemical equation Reactants—starting substances Products – substances that are formed in the chemical reaction Symbols that are used: + separates two or more products or reactants  separates reactants from products Identifies a solid state Identifies a liquid state Identifies a gaseous state (aq) Identifies a water solution

Word vs. Formula Word equations– equations that uses words to describe a chemical reaction Iron and chlorine react to produce iron (II) chloride Formula equations– equations that uses chemical formulas to describe a chemical reaction Fe(s) + Cl2(g)  FeCl2(s)

Types of Chemical Equations Synthesis Reactions When two or more reactants combine to form a product. A + B  AB 2Fe(s) + 3Cl2(g)  2FeCl3(s)

Types of Chemical Equations Decomposition Reactions When a single reactant breaks down into two or more products AB  A + B 2NaN3(s)  2Na(s) + 3N2(g)

Types of Chemical Equations Combustion Reaction When oxygen combines with a reactant and releases energy in the form of heat and light 2H2(g) + O2(g)  2H2O(g) CH4(g) + O2(g)  CO2(g) + 2H2O(g)

Types of Chemical Equations Replacement reactions Replacing an element in a compound with a different element Single Replacement A + BX  AX + B Cu(s) + 2AgNO3(aq)  2Ag (s) + Cu(NO3)2(aq)

Types of Chemical Equations Double Replacement Reactions AX + BY  BX + AY KCN(aq) + HBr(aq)  KBr(aq) + HCN(g)