Balancing Chemical Equations
1) Know the name of each reactant that is used and each product formed.
2) Find the correct formulas for each reactant and each product, and use them to write the "unbalanced" equation.
3) Preserve the law of conservation of matter by conserving atoms.
Example A:
1) Hydrogen and iodine react to form hydrogen iodide
2) H2 + I2 --> HI
3) H2 + I2 --> 2 HI (balanced) [Add another HI to conserve atoms]
Example B:
1) Hydrogen bromide and oxygen react to form water and bromine
2) HBr + O2 --> H2O + Br2
3) HBr + O2 --> 2 H2O + Br2 [Add another H2O to conserve O atoms]
4 HBr + O2 --> 2 H2O + Br2 [Add 3 more HBr to conserve H atoms]
4 HBr + O2 --> 2 H2O + 2 Br2 [Add another Br2 to conserve Br atoms]
Replacement (Single & Double)