Balancing Chemical Equations By: Jason R. Steele

Law of Conservation of Matter A natural law describing the fact that matter is neither created nor destroyed in any process Simply means that: The amount of matter that you start with has to equal to the amount of matter that you end with

For Chemical Reactions This Means That: The amount of reactants has to equal the amount of products. Matter cannot be created or destroyed through a chemical reaction. Chemical equations have to be balanced.

Balancing Chemical Equations Example: HCl + NaOH NaCl + H2O H=2 H=2 Cl=1 Cl=1 Na=1 Na=1 O=1 O=1 The equation is balanced because the number of atoms in the reactants are equal to the number of atoms in the products.

Balancing Chemical Equations Rules Before beginning to balance an equation, check each formula to see that it is correct. NEVER change a formula during the balancing of an equation. Balancing is done by placing coefficients in front of the formulas to insure the same number of atoms of each element on both sides of the arrow.

Balancing Chemical Equations Example: H2 + O2 H2O H=2 O=2 H=2 O=1 H2 + O2 2 H2O H=2 O=2 H=4 O=2 2H2 + O2 2 H2O H=4 O=2 H=4 O=2

Balancing Chemical Equations Example: Cu + AgNO3 Cu(NO3)2 + Ag Cu=1 Ag=1 N=1 O=3 Cu=1 Ag=1 N=2 O=6 Cu + 2AgNO3 Cu(NO3)2 + Ag Cu=1 Ag=2 N=2 O=6 Cu=1 Ag=1 N=2 O=6 Cu + 2AgNO3 Cu(NO3)2 + 2Ag Cu=1 Ag=2 N=2 O=6 Cu=1 Ag=2 N=2 O=6

Balancing Chemical Equations Example: Sodium bicarbonate + citric acid carbon dioxide, water, and sodium citrate. Empirical Formula: NaHCO3 + H3C6H5O7 CO2 + H2O + Na3C6H5O7

Balancing Chemical Equations Example: NaHCO3 + H3C6H5O7 CO2 + H2O + Na3C6H5O7 Na=1 H=9 C=7 O=10 Na=3 H=7 C=7 O=10 3NaHCO3 + H3C6H5O7 CO2 + H2O + Na3C6H5O7 Na=3 H=11 C=9 O=16 Na=3 H=7 C=7 O=10 3NaHCO3 + H3C6H5O7 3CO2 + H2O + Na3C6H5O7 Na=3 H=11 C=9 O=16 Na=3 H=7 C=9 O=14 3NaHCO3 + H3C6H5O7 3CO2 + 3H2O + Na3C6H5O7 Na=3 H=11 C=9 O=16 Na=3 H=11 C=9 O=16

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