balancing chemical equations

Balancing Chemical Equations

Steps to Balance Equation

• Chemical Equation Example:

  • Initial equation: ____ C3H8 + ____ O2 ➙ 3 CO2 + 4 H2O

Balancing Hydrogen

• Step b:

  • A coefficient of 4 must be placed in front of H2O.

  • Equation becomes: ____ C3H8 + ____ O2 ➙ 3 CO2 + 4 H2O

  • Atom Count:

    • Recount the number of atoms of each element.

      • Carbon (C): 3

      • Hydrogen (H): 8

      • Oxygen (O): Check post-reaction.

Balancing Oxygen

• Step c:

  • To balance oxygen, a coefficient of 5 must be placed in front of O2.

  • New equation: ____ C3H8 + 5 O2 ➙ 3 CO2 + 4 H2O

  • Atom Count:

    • Carbon (C): 3

    • Hydrogen (H): 8

    • Oxygen (O):

      • Products: 3 CO2 (6 O) + 4 H2O (4 O) = 10 O total.

      • Reactants: 5 O2 (10 O total).

Final Check

• Step d:

  • After calculating, the same number of atoms of each element appears on both sides of the equation:

    • C = 3, H = 8, O = 10.

  • Balanced Reaction:

    • The combustion of propane is now balanced as: C3H8 + 5O2 ➙ 3CO2 + 4H2O.

Summary of Atom Counts

• Reactants:

  • C = 3

  • H = 8

  • O = 10

• Products:

  • C = 3

  • H = 8

  • O = 10

• Both sides of the equation have identical atom counts; the reaction is balanced.