Balancing equations.notebook
March 13, 2013
Chapter 11: Chemical Reactions
Part 1:Balancing Equations
Feb 21­3:05 PM
Chemical Equations
Reactants à Products
Arrow means forms, yields, produces.
Iron + oxygen à iron (III) oxide
Methane + oxygenà carbon dioxide + water
Feb 21­3:05 PM
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Balancing equations.notebook
March 13, 2013
**See p 323 for symbols used in Chemical Equations.
+ separates two reactants or two products
yields à separates reactants from products
Double arrow indicates reversible reaction
Feb 21­3:05 PM
(s) Solid
(l) Liquid
(g) Gas
(aq) aqueous = dissolved in water
heat or delta above arrow indicates heat supplied
Formula above arrow indicates catalyst
Feb 21­3:05 PM
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Balancing equations.notebook
March 13, 2013
Chemical equations represent chemical reactions
Skeleton equation– does not tell relative amounts of reactants or products
Fe + O2à Fe2O3
H 2
O2à H2O + O2
Feb 21­3:05 PM
Why do we Balance Equations?
• Law of Conservation of mass
• Mass is conserved in a chemical reaction
• Mass of Reactants = Mass of Products
• Must have the same number of atoms of each type on each side of the reaction
Feb 21­3:05 PM
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Balancing equations.notebook
March 13, 2013
Balance equations • Change coefficients in front of reactants and/or products
• Never, never, never change subscripts on chemical formulas.
Feb 21­3:05 PM
Balancing Equations
C + O2 à CO2
H2 + O2 à H2O
Al + O2 à Al2O3
Feb 21­3:05 PM
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Balancing equations.notebook
March 13, 2013
Cu + AgNO3 à Cu(NO3)2 + Ag
AgNO3 + H2SO4 à Ag2SO4+ HNO3
Feb 21­3:05 PM
Al2(SO4)3 + Ca(OH)2 à Al(OH)3 + CaSO4
HCl + Al(OH) 3 à AlCl3 + H 2 O
KOH + H3PO4 à K3PO4 + H2O
Feb 21­3:13 PM
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Balancing equations.notebook
March 13, 2013
C6H6 + O2 ­­­> CO2 + H2O C6H6 + O2 ­­­> CO + H2O Feb 22­1:06 PM
Mar 13­2:45 PM
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