CHEMICAL EQUATIONS

• A chemical equation uses symbols and formulas to

  describe a chemical reaction.
• Reactants - elements or molecules involved in the

  chemical reaction and are written on the left side.
• Products - elements or molecules produced in the

  chemical reaction and are written on the right.
• The reactants and the products are separated by

  an arrow that means “produces”.
• Law of Conservation Of Mass:

  Both sides of an equation must be equal.
• Chemical equations must follow the Law of Conservation of

  Mass:

  The total mass of the reactants is always equal to the total mass

  of the products
• Mass is not lost or destroyed
• The # of atoms of reactants must equal the # of atoms of

  product
• BALANCING EQUATIONS:

  To determine if an equation is

  balanced, count all the atoms

  on each side of the equation.
• To balance the equation, coefficients

  (large numbers in front of molecules)

  may be added
• Subscripts (small lower numbers) MAY

  NOT be changed.