2/22/10
Post date: Feb 22, 2010 12:2:11 AM
Bell Ringer: Write the name of C6H12O6 (prefix for 12 is "dodeca").
Writing formulas when you have the name
Decide whether compound is ionic or covalent
Write symbols for each element involved
If covalent, use prefixes to decide what number subscripts go with each element's symbol
If ionic, use the valence numbers from the periodic table and "cross the charges" to figure out what number subscripts go with each element's symbol
Transition metals
Transitions metals are the middle section of the periodic table that we've ignored from now
These don't follow an easy pattern for valence numbers, and frequently one element has multiple valences that you may observe (e.g. Iron can have a charge of +2 or +3)
When writing the name of an ionic compound with a transition metal, use a roman numeral to show its charge (e.g. Iron which has a charge of +2 is written as Iron (II). This holds true in compounds, as well - Iron (II) chloride means the iron has a charge of +2)
All transition metals form ions with positive charges
All transition metals form ionic bonds
Below are the possible charges of the transition metals:
Ionic compounds with transition metals
Writing formulas (if given the name)
Write the symbol of each element in the compound
Write the charge for each symbol (for transition metal, write "+" and the number from the roman numeral)
Cross the charges
Example: Iron (III) oxide
Writing names (if formula is given)
Reverse the cross to find the charges for each symbol
Check the charge on the second symbol using the periodic table to make sure it is right (if not, double or triple all charges to make the charge on the last symbol correct)
Write the name of the compound as you normally would, but include the charge of the transition metal in roman numerals in parentheses.
e.g. CuCl
e.g. FeO
Naming Ionics assignment (due tomorrow):
Write the names of the following compounds (be sure to include the charge for any transition metals):
1. FeI2
2. MnF3
3. CrCl2
4. CuS
5. CdBr2
6. Cu3N2
7. NiO2
8. TiS
9. Fe2O3
10. ZnCl2
Write the formulas of the following compounds
11. Sodium chloride
12. Hydrogen fluoride
13. Copper (I) oxide
14. Copper (II) oxide
15. Magnesium phosphide
16. Cobalt (II) sulfide
17. Nickel (III) nitride
18. Titanium (II) phosphide
19. Potassium bromide
20. Zinc (II) oxide