What Are Common Mistakes in Naming Complex Ions?

[skander]

Homework Statement

I'm having trouble with naming complex ions. My textbook has given me a few rules but the examples they give seem to contradict them. These are all the rules I know, can someone tell me if they are right and if I am missing any?

Homework Equations

Start naming with negative ligands then neutral and then the central ion using roman numerals such as di, tri, tetra, penta, and hexa.
Write in parantheses the oxidation of the central ion.
If the complex ion is negatively charged add the suffix -ate.

The Attempt at a Solution

So [HgCl4]2- should be tetrachloromercurate(II)

Is this answer and the equations correct? Thanks.

 

[Gokul43201]

Yes, that's correct.

See also: http://www.chemistry.wustl.edu/~edudev/LabTutorials/naming_coord_comp.html

 

[Blueshift5]

Your equations and attempt at a solution are mostly correct. However, there are a few things to keep in mind when naming complex ions:

1. The negative ligands should be listed in alphabetical order before the neutral ligands. For example, [Fe(CN)6]4- should be named hexacyanoferrate(II), not cyanohexaferrate(II).

2. The roman numerals indicate the oxidation state of the central ion, not the number of ligands. So for [HgCl4]2-, the correct name would be tetrachloromercurate(II), not tetrachloromercurate(IV).

3. When naming complex ions with multiple central ions, use the prefixes bis-, tris-, tetrakis-, etc. For example, [Co(NH3)5Cl]Cl2 would be named pentaamminechlorocobalt(III) chloride.

4. If the complex ion is positively charged, the suffix -ium is added to the central ion's name. For example, [Cu(NH3)4]2+ would be named tetraamminecopper(II) ion.

Overall, it's important to follow the correct order and use the correct prefixes and suffixes when naming complex ions. I would suggest practicing with more examples and consulting with your textbook or professor if you continue to have trouble.