1. Ionic Bonds And Ionic Compounds
Section 7.2
Ionic Bonds
And
Ionic Compounds

2. Formation of an Ionic Bond
Compound
A chemical combination of two or more different elements
Binary compounds when there are exactly two different elements

3. Na + Cl  Na+ + Cl- + energy
P. 210 shows chemical reactions that form ionic bonds and release energy
Sodium and chlorine gas produce a white crystalline solid
Na + Cl  Na+ + Cl- + energy
This is called a chemical equation.

4. What Happened? + Sodium transferred one valence electron to chlorine.
[Na]+ + [Cl]- + energy +
This is the electron-dot structures

5. Types of Ionic Compounds
Electrostatic force holds the charged atoms together is the ionic bond.
Metal and non-metal ionic bond are called oxides.
Most other ionic compounds are called salts.

6. Names Sodium + Chlorine forms sodium chloride Sodium is a metal
Chlorine is a non-metal
Change chlorine to chloride in the name of the compound

7. p. 210 b
Ribbon of magnesium metal burns in air, it forms the ionic compound magnesium oxide.
Magnesium is a metal
Oxygen is a non-metal
Notice the name, oxygen became oxide.
Is this a binary ionic compound?

8. Questions Explain how an ionic compound forms from these elements
sodium and nitrogen
lithium and oxygen
strontium and fluorine
aluminum and sulfur

9. Properties of Ionic Compounds
Physical structure
Ratio of positive and negative ions
Ions are packed into repeating pattern
* No single unit of Na and Cl exists, there are many Na+ and Cl- ions in a 1 to 1 ratio.

10. Question
What determines the ratio?

11. Common Ionic Compounds
Carpet: calcium carbonate
Ceramics/glass: calcium carbonate, lithium borate, magnesium silicate, sodium carbonate
Glossy Paper: aluminum silicate, calcium carbonate, sodium sulfate, calcium oxide, sodium carbonate, titanium(IV) oxide
Toothpaste: calcium carbonate, sodium carbonate, sodium-hydrogen carbonate, sodium fluoride

12. Crystal Lattice Three dimensional geometric arrangement of particles
Each positive ion is surrounded by negative ions and each negative ion is surrounded by positive ions
The number of ions and the ratio determine the size and shape

13. Examples Minerals More than 1/3 of all known minerals are silicates
Halides
Borates
Carbonates
What elements do you think are in these?

14. Physical Properties Melting point - high Boiling point - high
Hardness - hard, rigid, brittle solids, hard to break apart
Depends on the strength of the ionic attraction
Conduct electricity
Solids: ions are locked into place, cannot conduct electricity
Melt or dissolve solids into solutions, the yes
Electrolytes are solutions that conduct electricity and important to humans

15. Energy Endothermic Energy is absorbed Exothermic Energy is released
Formation of ionic compounds
Forms more stable system so lower energy state, release energy

16. Lattice Energy
Energy required to separate 1 mol of the ions in an ionic compound
The greater the lattice energy, the stronger the force of attraction ( harder to separate)

17. Summary
Ionic compounds contain ionic bonds formed by the attraction of oppositely charged ions.
Ions in a ionic compound are arranged in repeating patterns known as a crystal lattice.
Ionic compounds properties are related to ionic bond strength.

18. Ionic compounds are electrolytes; they conduct an electric current in the liquid phase and in aqueous solution.
Lattice energy is the energy needed to remove 1 mol of ions from its lattice.

19. Questions
Explain how an ionic compound made up of charged particles can be neutral?
Describe the energy change associated with ionic bond formation, and relate it to stabillity.
Identify three physical properties of ionic compounds that are associated with ionic bonds, and related them to bond strength.

20. Explain how ions form bonds, and describe the structure of the resulting compound.
Relate lattice energy to bond strength.
Use electron configurations, orbital notations and electron dot structures to represent the formation of an ionic compound from the mental strontium and the non-metal chlorine.

21. Question
Using the elements aluminum and oxygen, determine the formula for the ionic compound.
Extension: Use Fe2+ and Fe3+ to combine with O2-
Determine the formula for the ionic compounds.

22. Each Student List a metal and a non-metal
Exchange papers and determine the ionic compound formed between them.

23. Exit Ticket
Determine the ionic compound formed from Mg and Cl and explain how it was formed.
Include its ratio