9
$\begingroup$

I recently came across a practice problem in my textbook asking me to name a few compounds using -ic and -ous endings. The exact wording is:

Write the name of each of the following ionic substances, using -ous and -ic endings to indicate the charge of the cation.

The first one was $\ce{CoCl2}$. However, cobalt has more than just two oxidization states (3, 2, 0, and -1).

So if it is one of the states in the middle, how do I decide whether to use -ous or -ic

Improve this question
$\endgroup$

1 Answer 1

Reset to default
11
$\begingroup$

Cobalt may possibly have all those other oxidation states (and others too) for this nomenclature system, we only care about the two most common oxidation states in ionic compounds: $\ce{Co^{2+}}$ and $\ce{Co^{3+}}$. Cobalt(II) compounds would thus be named cobaltous and cobalt(III) compounds would be cobaltic. Which is yours?

Improve this answer
$\endgroup$
5
  • $\begingroup$ Chloride is -1 and it's Cl2 so Cobaltous. Thanks! $\endgroup$
    – 735Tesla
    Commented Jul 31, 2014 at 0:38
  • $\begingroup$ -1 as in the charge, not your answer. That was really helpful! +1 $\endgroup$
    – 735Tesla
    Commented Jul 31, 2014 at 0:38
  • $\begingroup$ Is there a reference you would recommend for finding the most common oxidization states? I can't find one in my book and online. $\endgroup$
    – 735Tesla
    Commented Jul 31, 2014 at 1:59
  • 1
    $\begingroup$ $\ce{Co^3+}$ oxidizes $\ce{Cl-}$. I know this from personal experience. $\endgroup$
    – A.K.
    Commented Aug 17, 2018 at 0:25
  • $\begingroup$ Depending on its ligands Co3+ might oxidize Cl- is closer to the truth $\endgroup$
    – Ian Bush
    Commented Aug 17, 2018 at 6:11

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.