-2
$\begingroup$

I am confused as to the meaning of fully oxidized, in the context of environmental chemistry (what is water soluble). While I believed that CO$_2$ was fully oxidized after reading http://hyperphysics.phy-astr.gsu.edu/hbase/Chemical/redoxea.html, I also read that SO$_2$ is a reducing agent. Additionally, looking at the electronegativities of carbon versus sulfur, they are the same. Thus, what types of chemicals would fully oxidized refer to?

$\endgroup$

closed as too broad by Todd Minehardt, airhuff, Jon Custer, Jan, Klaus-Dieter Warzecha Mar 15 '17 at 3:50

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • $\begingroup$ Highest oxidation state $\endgroup$ – Mithoron Mar 14 '17 at 19:19
  • $\begingroup$ A couple notes: carbon and sulfur do have similar electronegativities, but that is not relevant to their possible oxidation states. Also, $\ce{SO2}$ is amphoteric in that it can act as an oxidant or reductant. The S in $\ce{SO2}$ is in the +4 oxidation state, but S can exist in oxidation states from +6 to -2. So, if $\ce{SO2}$ becomes oxidized to $\ce{SO3}$ for example (S goes from +4 ox state to +6 ox state), then $\ce{SO2}$ indeed would have acted as the reducing agent for that reaction (S was oxidized, another reactant was reduced). $\endgroup$ – airhuff Mar 14 '17 at 20:35
1
$\begingroup$

It comes down to the oxidation number of the element in the compound. From the link you provided, $\ce{CH4}$ has carbon in its most reduced form, with an oxidation number of $-4$. Carbon can't become any more reduced because a $-5$ state would imply that carbon had $9e^-$ in its valence shell, which would be highly unfavorable. Similarly, $\ce{CO2}$ has carbon in its most oxidized form, with an oxidation number of $+4$. Carbon can't become any more oxidized because a $+5$ state would imply that carbon lost an electron from its inner shell, which would be highly unfavorable.

$\endgroup$
  • $\begingroup$ My only minor nitpick with this answer is that there is no tie in to the OP's (rather confusing) request for an answer in the context of environmental chemistry and water soluble compounds (which methane is obviously not). Still, I thought this was overall a straight-forward, solid +1 answer to the title question ;) $\endgroup$ – airhuff Mar 15 '17 at 0:36

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