# How many atoms can be reduced in a single redox reaction?

I am doing high school chemistry and I am busy working with redox reactions.

The explanation in my text book, of how a redox reaction works, left me a bit confused as to how many atoms can be reduced/oxidized in a single reaction equation.

Can only one atom (species) be reduced/oxidized in a single equation or can there be more than one reduced/oxidized in the same chemical equation?

All of the reaction equations I have come across so far have just one atom reduced and one atom oxidized, for example:

$$\ce {Mg(s) + 2HCl(aq) -> H_2(g) + MgCl_2(aq)}$$

In this reaction only Mg is oxidized and only H is reduced. Is there a reaction in which more than one species of atom it reduced or oxidized?

• Redox reactions can be much more complicated then that. – Mithoron Oct 12 '17 at 14:27
• I know they get much more complex. I am not doing very complex ones yet. I just chose a simple one to try illustrate my question, which is a very simple question. – user53273 Oct 12 '17 at 14:33
• Yes, there can be more and yes/no questions are suitable for this site. – Mithoron Oct 12 '17 at 14:36
• Thanks. That really helps. I think my text book spoke as if only one could be reduced/oxidized at a time because I would not need to do more complex ones yet. Unfortunately I don't have enough reputation to up-vote you :-( – user53273 Oct 12 '17 at 14:42
• I'd rather point out that the reactions in which multiple elements get oxidized/reduced are a relative minority (in school chemistry, at least). True, you'd encounter pretty complex reactions further on, but their complexity stems from other reasons; despite it, most of the times there would be only one oxidant and one reducing agent. – Ivan Neretin Oct 12 '17 at 14:50

$$\ce{CH3-SH + 3 O2 -> SO2 + CO2 + 2 H2O}$$
Thereby the oxidation states of sulfur and carbon change from $-2$ to $+4$ and the oxidation state of oxygen from $\pm0$ to $-2$. So sulfur and carbon atoms are both oxidized while oxygen is reduced.