Equations

Chemical ReactionWhen a substance

goes through a reaction and changes

into another substance.

Chemical EquationsA formula which

shows how elements or compounds react to form new compounds

2H+ + O-2 H2O

Parts of a chemical equations

• Reactants

• Yield Sign

• Products

ReactantsThe elements or

compounds that are found on the left side

of the yield sign

Yield SignAn arrow found in the equation which works

like an equal sign

Products

The elements or compounds that are

found on the right side of the yield sign

Coefficient

Is the number found in front of an ion or

compound. It tells the number of that ion or compound you have

Balanced Equation

For each element in a chemical equation, the same number of each element must be found on the left side of the

arrow as on the right side

All chemical equations must be balanced.

To balance an equation, you can change the

coefficient. However, you can never, never, never change the subscript.

Symbols used in Chemical Equations

(l) The chemical is a liquid.

(s) The chemical is a solid.

(g) The chemical is a gas.

(aq) The chemical is aqueous (dissolved in water).

Synthesis Reactions

A reaction where the reactants combine to

form a bigger compound (also known as combination)

Synthesis Reactions

2H+ + O-2 H2O

Decomposition Reaction

A reaction where the reactants break down

(decompose)

Decomposition ReactionH2O 2H+ + O-2

Single Displacement Reaction

A reaction where one element replaces another element in a compound

Single Displacement Reaction

2Al3+ + 3Ag2S Al2S3 + 6Ag2+

Double Displacement Reactions

A reaction where the positive ion of two

compounds switch, which forms two new compounds

Double Displacement Reactions

HCl + NaOH NaCl + H2O

Combustion

A reaction in which a compound (often

carbon) reacts with oxygen

CombustionC + O2 CO2

CH4 + 2O2 CO2 + 2H2O

C3H8 + 5O2 3CO2 + 4H2O

C6H12O6 + 6O2 6CO2 + 6H2O

Redox ReactionsA reaction where one

compound loses electrons and becomes a smaller compound, while another compound gains

electrons and becomes a bigger compound.

Redox Reactions

C6H12O6 + 6O2 6CO2 + 6H2O

Oxidized Compound

The compound that loses electrons and becomes a

smaller compound

Reduced Compound

The compound that gains electrons and becomes a

bigger compound

Oxidation-Reduction Reaction

Another name for the Redox Reaction