5 Steps to a 5 AP Chemistry 2019

(^60) › STEP 4. Review the Knowledge You Need to Score High
Examples:
[Ru(NH 3 ) 5 (N 2 )]Cl 2 coordination compound
[Ru(NH 3 ) 5 (N 2 )]^2 + complex ion (cationic)
[PtNH 3 Cl 2 (C 5 H 5 N)] coordination compound
[IF 6 ]- complex ion (anionic) (the name must end in -ate)
K[IF 6 ] coordination compound (same -ate ending)
If everything in the formula is enclosed within one set of brackets, the entire name
will be one word. If there is material outside the brackets, this outside material is named
separately.
Just as with simpler compounds, cations are always named before anions. Thus,
a cationic complex would be the first word in the name, and an anionic complex would be
the last word in a name (with an ate ending).
Examples:
[Ni(H 2 O) 4 Cl 2 ] tetraaquadichloronickel(II)
[Co(NH 3 ) 6 ]Cl 3 hexaamminecobalt(III) chloride
K 2 [PtCl 4 ] potassium tetrachloroplatinate(II)
When naming a complex, or when writing the formula for a complex, the ligands
are listed alphabetically. Again, do not forget that metals are first in the formula and last
in the name.
The names of anionic ligands always end in an o. Neutral ligands are basically
unchanged. Two common exceptions in the case of neutral ligands are NH 3 = ammine
(note the double m), and H 2 O = aqua. Other common ligands and their names are listed
in the appendixes.
Multiple identical ligands have prefixes added to designate the number of such ligands:
2 di- 5 penta- 8 octa-
3 tri- 6 hexa- 9 nona-
4 tetra- 7 hepta- 10 deca-
Examples:
[Co(NH 3 ) 6 ]Cl 3 hexaamminecobalt(III) chloride
[Cr(NO) 4 ] tetranitrosylchromium(0)
If the ligand name contains a prefix or begins with a vowel (except ammine and aqua),
alternative prefixes should be used:
2 bis- 5 pentakis- 8 octakis-
3 tris- 6 hexakis- 9 nonakis-
4 tetrakis- 7 heptakis- 10 decakis-
When using the alternative prefixes, it is common practice to enclose the name of
the ligand within parentheses. Either type of prefix is added after the ligands have been
alphabetized.
Examples:
[Cr(en) 3 ]Cl 3 Tris(ethylenediamine)chromium(III) chloride
K 2 [Ge(C 2 O 4 ) 3 ] Potassium tris(oxalato)germanate