1. 4.1 Representing Ionic Compounds

2. Prayer
Lord, you said that when two or three would gather together in your name, then you would be present with them.
I am praying by myself (or ‘on the Internet’) but I am uniting myself with many individual Christians throughout the world
who, though separate, are gathered together in another sense to pray to you, and I trust that you are with me now.

3. Forming Ionic Compounds
Elements can combine to make ionic compounds
Ionic Compound: A compound composed of oppositely charged ions; a metal and a non-metal.
What Is Na? Is it a metal or a non metal? Positive or negative charge?
What is Cl? “ “

4. Cations & Anions & Charges
When an atom loses or gains electron and becomes charged, it becomes an ion
When an atom loses an electron, it becomes positive
When an atom gains an electron, it becomes negative
Positively Charged Ion = Cation
Negatively Charged Ion= Anion
- If I presented you with an elemental symbol, how would you determine whether it was a Metal or a Non-Metal?
- Metals = Positive charges ; Non-Metals = Negative charges ?

5. When electrons are TRANSFERRED from one atom to another, an Ionic Bond is taking place

6. Properties of Ionic Compounds
State
Solids
Conductivity
Yes; in liquid!
Structure
Crystal structure (Salt)
Melting points
Very high
Boiling points

7. Valence Electrons
There are patterns related to the arrangement of electrons in atoms in the periodic table.
Elements in the same Groups have the same number of valence electrons
Valence Electrons: electrons in the outer energy level
These are involved in chemical bonding between elements

8. Valence Electrons
It helps to know the number of valence electrons that each group has so that you can:
Predict formation of compounds
Name compounds
Write chemical formulas

9. Naming Binary Compounds
2 ways to identify a compound:
Chemical Name
Chemical Formula
International Union of Pure and Applied Chemistry (IUPAC) develops rules for naming compounds so that scientists around the world can have the same names for the same compounds.

10. RULES: First identify the Positive Ion (the metal cation)
Second part of the name always identifies the Negative Ion (non-metal anion)
Change the ending of the Negative Ion/Non-metal anion to –ide
Chemical Names
Manesium & Phosphorus
Magnesium Phosphide
Sodium & Chlorine
Sodium Chloride
Calcium & Bromine
Calcium Bromide
Aluminum & Oxygen
Aluminum Oxide

11. Chemical Formula Metal Non-metal Charges? Flip-flop!
If the charge is 1? Drop it.

12. FOR EXAMPLE:
Magnesium Chloride
Mg Cl 2+ 1-
Mg1Cl2
MgCl2

13. Multivalent Metals
Check out your periodic table; you may notice some elements have more than one charge! These are called MULTIVALENT METALS
Copper, for example, can form ions with either a charge of +1 or +2.

14. In your booklet: Stock System vs. Classical System of naming
Ie. Copper (II) Sulfide. OR Cupric Sulfide
Check the charges, refer to the BACK of your pink periodic table.

15. Writing Chemical Formulas and Naming Ionic Compounds with a Multivalent Metal
When naming a compound that has a multivalent ion, you must include a Roman numeral to indicate which charge the ion has.
Ie. Copper (II) Sulfide: CuS

16. STEPS
Cu3N
SnS2
1. Identify the metal
Copper (Cu)
Tin (Sn)
2. Is it multivalent? Does it have more than one charge? Check periodic table!
Cu +1 and Cu +2
Sn +2 and Sn +4
3. How many of each ion do you have?
3 Copper: 1 Nitrogen
1 Tin: 2 Sulfur
4. Note the charge of the non-metal -3 -2
5. (-) and (+) charges must balance so that the net charge is zero.
Neg. Charges = -3
SO Pos. Charges = +3
Neg. Charges = -4
SO Pos. Charges = +4
6. What charge must the metal have to balance the non-metal?
3 (Cu?) = 3+
Therefore, the charge on Cu must be +1
1(Sn?) = +4
Therefore, the charge on the tin must be 4+
7. Write the name of the metal ion
Copper (II)
Tin (IV)
8. Write the name of the compound
Copper (II) Nitride
Tin (IV) Sulfide

17. Example: Sn3P4 Tin Yes: Sn +2 and Sn+4 3 Tin: 4 Phosphorous -3
STEPS
1. Identify the metal
2. Is it multivalent? Does it have more than one charge? Check periodic table!
3. How many of each ion do you have?
4. Note the charge of the non-metal
5. (-) and (+) charges must balance so that the net charge is zero.
6. What charge must the metal have to balance the non-metal?
7. Write the name of the metal ion
8. Write the name of the compound
Tin
Yes: Sn +2 and Sn+4
3 Tin: 4 Phosphorous -3
Total Negative Charge: -12
SO the Total Pos. Charge = +12
(Sn?) = 12+ Therefore the charge of tin must be 4.
7. Tin (IV)
8. Tin (IV) Phosphide

18. Sn3P4
Sn3P4
Sn 4 P 3
(Sn +4) (P -3)
You could also do the reverse cross-over method: