balancing equations
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Balancing Equations. Law of Conservation of Mass. The Law of Conservation of Mass states: that mass is neither created nor destroyed in any chemical reaction . Therefore balancing equations requires the same number of atoms on both sides of a chemical reaction. - PowerPoint PPT PresentationTRANSCRIPT
Balancing Equations
Law of Conservation of Mass
The Law of Conservation of Mass states: that mass is neither created nor destroyed in any chemical reaction. Therefore balancing 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
Balance elements in the following order:
1. Nonmetals2. Metals3. Polyatomic ions4. Hydrogen5. Oxygen
Polyatomic Ions
When balancing polyatomic ions treat them as one unit if they appear on both sides of the equation.
Balancing Equations
Complete an atom inventory.
N2 + H2 NH3
__N____H__
2 1
2 3
Balancing Equations
Nothing is balanced.Balance the nitrogen first by placing a coefficient of 2 in front of the NH3.
N2 + H2 2NH3
Balancing Equations
Hydrogen is not balanced.Place a 3 in front of H2.
N2 + 3H2 2NH3Complete a final atom inventory.
__N____H__
2 2
6 6
Balancing Equations
Complete an atom inventory.
C3H8 + O2→ CO2+ H2O
__C____H____O__
3 1
8 2
2 3
Balancing Equations
Nothing is balanced.Balance the carbon first by placing a coefficient of 3 in front of the CO2.
C3H8 + O2 → 3CO2+ H2O
Balancing Equations
Now balance the hydrogen by placing a 4 in front of the water on the products side.
C3H8 + O2 → 3CO2+ 4H2O
Balancing EquationsBalance the oxygen on the reactants side with a coefficient of 5.C3H8 + 5O2 → 3CO2+
4H2OComplete a final atom inventory.
__C____H____O__
3 38 8
10 10
Balancing Equations
Complete an atom inventory.
BF3+ Li2SO3→ B2(SO3)3+ LiF
__B__ __F__ __Li____SO3__
1 2 3 1
2 11
3
Balancing Equations
Nothing is balanced.Balance the fluorine first by placing a coefficient of 3 in front of the LiF.
BF3+ Li2SO3→ B2(SO3)3+ 3LiF
Balancing Equations
Now balance the boron by placing a 2 in front of the BF3 on the reactants side.
2BF3+ Li2SO3→ B2(SO3)3+
3LiF Notice we’ve unbalanced the fluorine, and now must adjust our coefficients.
Balancing Equations
Now balance the boron by placing a 2 in front of the BF3 on the reactants side.
2BF3+ Li2SO3→ B2(SO3)3+
6LiF Notice we’ve unbalanced the fluorine, and now must adjust our coefficients.
Balancing EquationsBalance the lithium sulfite on the reactants side with a coefficient of 3.
Complete a final atom inventory.2BF3+ 3Li2SO3→ B2(SO3)3+ 6LiF
2 2 6 6
6 6 3
3
__B__ __F__ __Li____SO3__
YOU ARE BALANCED!!