Symbolic notation used by chemists to represent a chemical reaction. Chemical Equation Symbolic notation used by chemists to represent a chemical reaction.

In a chemical equation, everything to the left of the arrow Reactant – starting materials In a chemical equation, everything to the left of the arrow

In a chemical equation, everything to the right of the arrow Product – ending materials In a chemical equation, everything to the right of the arrow

Number in front of a formula. Tells how many formula units are present. Coefficient

Balanced chemical equation Demonstrates conservation of mass. Same # of each element on both sides. Balanced chemical equation

Chemical equations demonstrate conservation of mass, charge (& energy) Chemical equations demonstrate conservation of

Synthesis Reaction with 1 product

Reaction with 1 reactant Decomposition Reaction with 1 reactant

Single Replacement Reaction of 1 element with 1 compound to produce a new element & a new compound

Reaction of 2 compounds to produce 2 new compounds. Double Replacement Reaction of 2 compounds to produce 2 new compounds.

Reaction with oxygen. One of the reactants must be O2. Combustion Reaction with oxygen. One of the reactants must be O2.

Decomposition AB  A + B

Synthesis A + B  AB

Single Replacement AX + B  A + BX

Double Replacement AX + BY  AY + BX

To predict if a single replacement reaction will occur, You must compare the reactivity of the free element with the corresponding element in the compound. Use Table J. If the stand-alone element is above the corresponding element in the compound, the reaction will take place. To predict if a single replacement reaction will occur,

2Na + MgCl2  2NaCl + Mg Na + MgCl2  ? Compare Na & Mg (both metals). Na is above Mg in Table J so the rxn occurs. 2Na + MgCl2  2NaCl + Mg Na + MgCl2  ?

Do the following reactions occur? Br2 + HF: Compare Br2 & F2 Mg + ZnCl2: Compare Mg & Zn Na + HCl: Compare Na & H2 Ag + LiBr: Compare Ag & Li No Yes Yes No

Stoichiometry Problems Use the relationship in the balanced equation to predict amounts consumed or produced. Use the equation to set up a ratio. Stoichiometry Problems

2 Moles of hydrogen! X 4 4/2 = X/1 so X = 2 2Na + 2H2O  2NaOH + H2 How many moles of hydrogen are produced when 4 moles of sodium reacts completely? 4/2 = X/1 so X = 2