Ionic Compounds and Bonding
- 2. Ionic Bonding Ionic Bonding occurs between metals and nonmetals. Electrons are transferred from the metal atoms to the nonmetal atoms. The driving force behind ionic bonds is that cations (+ ion) give up electrons and anions (- ions) accept electrons to make Noble Gas Configurations
- 3. Ionic Bond Formation Check your Bohr models to see how many electrons an element will want to lose or gain. Mark each family. The resulting electrostatic forces are what hold the two ions together. Total charges on an ionic compound are equal but opposite.
- 6. Draw what happens when sodium reacts with chlorine to form sodium chloride DRAW THE DOT AND CROSS DIAGRAM TOO.
- 7. Naming Ionic Compounds 1. Always name the cation (positively charged ion) first, the anion (negatively charged ion) second 2. Use the name of the cation without any alterations. 3. Use the root and “-ide” to the end for anions 4. For the transition metals, use brackets and Roman Numerals after the name to denote its charge
- 8. Examples LiI BeBr2 Aluminum Sulfide FeCl2 Iron (III) Chloride Lithium Iodide Beryllium Bromide Al2S3 Iron (II) Chloride FeCl3
- 9. Polyatomic Ions Poly – Many Atomic - Atoms Ions formed of multiple atoms usually covalently bonded together and should be treated as one entity. Nitrate: NO3 -
- 10. Polyatomic Ions Pb2+ + 2 NO3 - → Pb(NO3)2 The brackets tell us that everything inside is doubled.
- 11. Common Polyatomic Ions NH4 + Ammonium CO3 2- Carbonate HCO3 - Hydrogen carbonate (Bicarbonate) PO4 3- Phosphate ClO2 - Chlorite ClO3 - Chlorate ClO4 - Perchlorate NO2 - Nitrite NO3 - Nitrate SO3 2- Sulfite SO4 2- Sulfate MnO4 - Permanganate OH- Hydroxide
- 12. Try These Iron (III) Nitrate Al2(CO3)3 KOH Silver (II) Sulfate Calcium Bicarbonate Fe(NO3)3 Aluminum Carbonate Potassium Hydroxide Ag2SO4 Ca(HCO3)2
- 13. Ionic Bonding Properties: Solids at room temperature Due to strong electrostatic interactions between the cation (+ ion) and anion (- ion). Tend to have high melting points Typically quite hard
- 14. Ionic Bonding Properties (cont’d) Poor conductors in solid state The electrons are being taken up in the bonding Great conductors when molten or aqueous When the ions dissociate the electrons are free to move and pass the charge
- 15. Ionic Bonding Properties (cont’d) Most dissolve or dissociate nicely in water Water has partial charges that interact with the ions’ charges
- 16. Interaction with water: Click here to watch video.
- 17. Ionic Structure Ionic compounds join together to form Crystal Lattice Structures The atoms arrange themselves in such a way that gives the structure stability
- 18. NaCl Crystal Lattice (Simple Cubic) NaCl Crystals
- 19. Determining the Crystal Structure We use a technique called X-Ray Crystallography X-rays are shot at a sample and will bounce off the atoms in a specific pattern according to how they’re arranged.
- 20. Click to watch video.
- 21. Crystal Structures A lot depends on the size of the ions. Na+ is relatively small compared to Cl- so it can slip in between the Cl- ions and form a simple cubic structure. Cs+ , however, is about the same size as Cl- so it’s more like packing ping- pong balls.