Chemical Reactions

Notes

Reactants ProductsSubstances that

undergo a change

New substances formed

Yields or Produces

Chemical Equations

• A representation of a chemical reaction

• Tells you the substances present before a change and after a change

Law of Conservation of Mass

• Mass is neither created nor destroyed in a chemical reaction

Balancing Equations

• In order to show that mass is conserved during a chemical reaction, a chemical equation must be balanced

Coefficients

• The numbers that appear before a chemical formula

• Can be changed in order to balance an equation

H2

3O2

4NH3

2H2PO4

C + O2 CO2

Cu + O2 CuO

H2 + O2 H2O

N2H4 + O2 N2 + H2O