SCIENCE

• Balancing Chemical Equations


  Balancing a chemical equation is much like the work of an accountant who has to show every penny that comes in and where it has gone to
• Law of Conservation of Mass

  Mass is neither created nor destroyed in any chemical reaction. Therefore balancing of equations requires the same number of atoms on both sides of a chemical reaction. The number of atoms in the Reactants must equal the Number of atoms in the Products
• Because of the principle of the Conservation of Matter, an equation must be balanced. It must have the same number of atoms of the same kind on both sides.
• Lavoisier


  1788
• Chemical Equations


  Reactant + Reactant = Product
• The mass of all the reactants (the substances going into a reaction) must equal the mass of the products (the substances produced by the reaction).
• A simple equation, such as the synthesis of Iron (II) sulfide

  • Fe + S FeS
• In a chemical equation, by convention, we use the arrow " " instead of the equals " = ".
• The last stage is to put in state of matter symbols, (s, l, g, aq), as appropriate (solid, liquid, gas, aqueous or dissolved in water)
• Balancing Equations


  1. List the atoms involved on each side

  2. Count up the atoms on each side

  3. Add "BIG" numbers to make up for any shortages

  4. Adjust totals until both sides have equal numbers of atoms
• Try to balance these equations using the same method:

  • Na + Cl2 NaCl
  • CH4 + O2 CO2 + H2O
  • Al + O2 Al2O3
  • Li + HNO3 LiNO3 + H2
• Here are the answers:
• A planet is an astronomical body that orbits around a star, such as Earth.
• The sun is the largest object in our solar system.
• Mercury is closest to the Sun and has no atmosphere.