9/24/10
Post date: Sep 24, 2010 3:24:2 PM
Questions about naming covalent compounds?
Quiz 5 - naming covalent compounds
Formulas for ionic compounds (review)
Write the chemical symbol for each element named, in the same order
Write the charge with each symbol
Cross the charges to get the subscripts
Naming ionic compounds
Write the name of each element
Change the ending of the last element to -ide
Check to see if you have any transition metals (elements from the middle section of the table)
If no transition metals, you're done!
If you have transition metals, specify the charge on the metal (see below)
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 more common transition metals (these are also listed on the periodic table in your planner):
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