Balancing Equations
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Valency Table
Table 1.5: A Valency Table
Positive ions
Negative ions
Name
Valence no.
Valence Sign
Symbol
Name
Valence no.
Valence Sign
Symbol
Aluminium
3
+
Al3+
Bromide
1
-
Br-
Carbonate
2
-
CO32-
Ammonium
1
+
NH4-
Barium
2
+
Ba2+
Chloride
1
-
Cl-
Calcium
2
+
Ca2+
Fluoride
1
-
F-
Chromium III
3
+
Cr3+
Hydrogen carbonate
(bicarbonate)
1
-
HCO3-
Copper
2
+
Cu2+
Hydroxide
1
-
OH-
Iodide
1
-
I-
Gold
3
+
Au3+
Hydrogen
1
+
H+
Nitrate
1
-
NO3-
Iron II
2
+
Fe2+
Oxide
2
-
O2-
Phosphate
3
-
PO43-
Iron III
3
+
Fe3+
Lead
2
+
Pb3+
Sulfate
2
-
SO42-
Magnesium
2
+
Mg2+
Sulfide
2
-
S2-
Nickel
2
+
Ni2+
Potassium
1
+
K+
Silver
1
+
Ag+
Sodium
1
+
Na+
Zinc
2
+
Zn2+
Valence 1-
COMPLETE THIS TABLE
Chloride
Cl1-
Valence 2-
Nitrate
NO31-
Hydroxide
OH1-
Example
Silver Nitrate
AgNO3
Not Known
Sulfate
(SO4) 2-
Carbonate
CO32-
Oxide
O2-
Example
Ammonium
Carbonate
(NH4)2CO3
Not Known
Sodium Na1+
Potassium K+1
Valence 1+
Silver Ag+1
Ammonium (NH4)+1
Barium Ba+2
Calcium Ca+2
Example
Calcium Nitrate
Ca(NO3)2
Example
Magnesium Sulfate
MgSO4
Magnesium Mg+2
Valence 2+
Zinc Zn+2
Iron Fe+2
(ferrous)
Lead Pb+2
Copper Cu+2
Valence 3+
Aluminium Al+3
Iron Fe+3
(ferric)
Not Known
Example
Iron Hydroxide
FeOH3
Example
Iron Sulfate
Fe2(SO4)3
Not Known
Example of balancing
chemical equations
Word Equation
Sodium chloride and Copper sulphate produces Sodium sulphate and copper chloride.
Chemical Reaction
Reactants
Element
Element
Na
Cl
Ion
Ion
Na+
Cl-
Products
+
+
Element
Element
Cu
SO4
Ion
Ion
Cu2+
SO42-
=
=
Balanced Ionic Compounds
NaCl
+
CuSO4
NaCl
Na
SO4
Ion
Ion
Na+
SO42-
+
+
Element
Element
Cu
Cl
Ion
Ion
Cu2+
Cl-
Na2SO4
+
CuCl2
Balanced Equations
Ionic Compound
2
Element
Balanced Ionic Compounds
Balanced Equations
Number
Element
Ionic Compound
Number
+
1
CuSO4
Ionic Compound
Number
=
1
Na2SO4
Ionic Compound
Number
+
1
CuCl2
Sodium Chloride and Copper Sulphate
Element
Na
Ion
Na+
Element
Element
Cl
+
Ion
Cl-
Cu
Element
SO4
Ion Ion
Cu2+ SO42-
+
Balanced Ionic Compounds
NaCl
+
CuSO4
Sodium Sulphate and Copper Chloride
Element
Na
Ion
Na+
Element
Element
SO4
+
Ion
SO42-
Cu
Cl
Ion Ion
Cu2+ Cl-
+
Balanced Ionic Compounds
Na 2SO4
Element
+
CuCl 2
Word Equation
Chemical Reaction
Reactants
Element
Element
Products
Element
Element
+
Ion
Element
Element
=
Ion
Ion
Ion
Ion
Ion
+
Balanced Ionic Compounds
+
+
Balanced Equations
Ionic Compound
Ion
=
Balanced Ionic Compounds
Element
+
Ion
+
Number
Element
Balanced Equations
Number
Ionic Compound
Number
=
Ionic Compound
Number
Ionic Compound
Word Equation
Chemical Reaction
Reactants
Element
Element
Products
Element
Element
+
Ion
Element
Element
=
Ion
Ion
Ion
Ion
Ion
+
Balanced Ionic Compounds
+
+
Balanced Equations
Ionic Compound
Ion
=
Balanced Ionic Compounds
Element
+
Ion
+
Number
Element
Balanced Equations
Number
Ionic Compound
Number
=
Ionic Compound
Number
Ionic Compound