1. Ionic Bonding and Salts
5.2

2. Ionic Bonds
Chlorine gains 1 e- and sodium loses 1 e-
Cl- and Na opposites attract
Forms ionic bond
Salt – an ionic compound that forms when a metal atom or a positive radical replaces the H of an acid

3. Ionic Compounds
Ionic cmpds are electrically neutral
Ions attract multiple opposite charged ions
Form crystals

4. Energy Changes and Bonds
E is required to
Make Na a gas
Remove an electron from Na
Separate Cl molecule
E is released when
An e- is added to Cl
Na+ and Cl- ions come together

5. Energy Changes
Lattice Energy – the energy associated with a crystal lattice relative to the energy of all constituent atoms separated by infinite distances
NaCl lattice E is higher than the amt. of E needed for previous steps in making NaCl = spontaneous rxn

6. Energy Changes
Lattice Energy changes for each compound
Lattice E needs to be overcome to break that bond as well
NaCl in water/MgO in water

7. Are not molecules – more like crystals Charge balances out 1 Cl=1 Na
Ionic Compounds
Are not molecules – more like crystals
Charge balances out 1 Cl=1 Na
Very strong ionic bonds
Very high melting and boiling points

8. Can’t conduct as solids – current can’t move
Ionic Compounds
Can’t conduct as solids – current can’t move
Can conduct when melted or dissolved – current can move
Hard and brittle
Typically solid at room temp

9. Depends on size and # of ions
Salt Crystals
Crystal Lattice – the regular repeating pattern in which a crystal is arranged
Depends on size and # of ions

10. Unit Cell
Unit Cell – the smallest portion of a crystal lattice that shows the 3-D pattern of the entire lattice