14.2 Balancing Chemical Equations H2 + O2 H20 Reactants = Products Left side = Right side

When balancing equations: The CAN”T be changed The CAN be changed 2H2 + O2 2H20

Coefficients must be whole numbers After writing the chemical equation, make a table of Balance each element, using . H2 + O2  H2O Reactants (BEFORE) Products (AFTER)

2H2 + O2  2H20    molecules atoms What must be conserved? What does this mean? What law ?

Mass is conserved and the number of atoms are also conserved Mass is conserved and the number of atoms are also conserved. This means that if we have 100 atoms on the reactant side, we must have 100 atoms on the product side. H2 + O2  H2O Balance this equation (coefficients) 2H2 + O2  2 H2O Determine out how many atoms Atoms are equal on both sides so they are

Recall Earlier Example When beryllium chloride reacts with sodium bromide, beryllium bromide and sodium chloride are formed. Write Word Equation: beryllium chloride + sodium bromide beryllium bromide + sodium chloride Write Unbalanced Chemical Equation: ___BeCl2 + ___NaBr ___BeBr2 + ___NaCl