3
Balancing Equations
Word Equations
What is the big idea?
The universe is balanced!
Balance the equation
2__Al(s) + __
3 I2(g)
Al
Reactants
2
I
6

2 AlI3(s)
__
Products
Al
2
I
6
Each element has the same number on each side
You can only put coefficients in front of each formula
The total number of atoms is the coefficient x the subscript
__C3H8(s)
5 O2(g)
+

__3 CO2(g)
6 Oxygen
10 Oxygen
+
+
4 H2O(g)
__
4
10 Oxygen
½ is allowed but not ¼……….
Oxygen
__C8H18(s)
+
12.5
__ O2(g)
25 Oxygen

8 CO2(g)
__
+
9 H2O(g)
__
16 Oxygen
+
9
25 Oxygen
½ is allowed but not ¼……….
Oxygen
Phase Symbols
(s)
solid
Fe(s)
(l)
liquid
H2O(l)
(g)
gaseous
O2(g)
(aq)
aqueous
NaCl(aq)
dissolved in water
Common Acids
HCl
Hydrochloric Acid
Stomach
H2SO4
Sulphuric Acid
Acid Rain
H3PO4
Phosphoric Acid
Coke
HNO3
Nitric Acid
Dissolving metals
Fluoride Treatment
CH3COOH Acetic Acid
Vinegar
H2CO3
Carbonated Beverages
Carbonic Acid
Hydrates
MgSO4.5H2O
Magnesium sulphate pentahydrate
BaCl2.6H2O
Barium chloride hexahydrate
FeSO4.H2O
Iron II sulphate monohydrate
Greek prefixes
1 – mono
7 - hepta
2 – di
8 - octa
3 – tri
9 – nona
4 – tetra
10 - deca
5 – penta
11 - undeca
6 - hexa
12 - dodeca
Word Equations
A solution of barium phosphate is mixed with aqueous sodium sulphate
to yield solid barium sulphate and aqueous sodium phosphate.
Ba3(PO4)2(aq) + 3 Na2SO4(aq) →
3 BaSO4(s) +
2 Na3PO4(aq)
A solution of aluminum chloride, carbon dioxide, and water can be prepared by
mixing pure aluminum carbonate with a solution of hydrochloric acid.
Al2(CO3)3(s)
+ 6 HCl(aq)

3 CO2(g)
+ 2 AlCl3(aq) +3 H2O(l)
What happens if you mix?
and
Combustible Material
Oxidizing Material
Who wants to try it?
Demo: Solid sucrose reacts with oxygen to produce carbon dioxide gas,
water, and energy. The catalyst H2SO4 initiates the reaction.
C12H22O11(s) + 12 O2(g)
H2SO4
12 CO2(g) + 11 H2O(l) + energy
The catalyst goes on top of the arrow
Workbook
Assignment # 3