Chemical Bonding III

1
Chemical Bonding III

• Polyatomic Ions

2
Polyatomic Ions

• 2 or more covalently bonded nonmetals which forms
  a charged ion
• Acts as a unit
• Forms ionic compounds with metals
• Charge remains constant for each ion
• Charge is characteristic of each ion

3
More on Polyatomic IonsCross the charges to make
compounds
Ion/Charge Name Example Name
OH- hydroxide NaOH Sodium hydroxide
NO3- Nitrate KNO3 Potassium nitrate
CN- Cyanide Mg(CN)2 Magnesium cyanide
NH 4 Ammonium NH4NO3 Ammonium nitrate
4
More on Polyatomic IonsCross the charges to make
compounds
Ion/Charge Name Example Name
CO3-2 Carbonate CaCO3 Calcium carbonate
SO4-2 Sulfate Na2SO4 Sodium sulfate
PO4-3 Phosphate Mg3(PO4)2 Magnesium phosphate
5
Polyatomic ions

• You will find a more comprehensive list of
  polyatomic ions on p. 155 of your text.
• Quiz
• Na PO4-3 ? ?
• Na3PO4 Cross the charges to make subscripts!!
• Name?
• Sodium phosphate

6
Polyatomic ions example problem 2

• Mg2 PO4-3 ? ?
• Cross the charges!!
• Mg3(PO4)2
• Name?
• Magnesium phosphate
• Prelab Properties of 2 solids lab.