Chemical Reactions Notes

Reactants Products Substances 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

H 2 3O 2 4NH 3 2H 2 PO 4

C+ O 2  CO 2

Cu + O 2  CuO

H 2 + O 2  H 2 O

N 2 H 4 + O 2  N 2 + H 2 O