In the redox reaction:
2FeS + 4.5 O(subscript 2)+ 2H(subscript 2)O > Fe(subscript 2)O(subscript 3) +
2H(subscript 2)SO(subscript 4)
Fe is oxidized or reduced (select one) from ___ to ___.
S is oxidized or reduced (select one) from ___ to ___.
You only need to know the definitions.
Oxidation is the loss of electrons; reduction is the gain of electrons.
To do loss and gain of electrons you use the oxidation states. Fe is +2 in FeS and +3 in Fe2O3. S is -2 in FeS and +6 in H2SO4.
DrBob222,
I understand that oxidation is a loss, but appears as an increase. I still have two questions.
1) Fe goes from +2 to +3, and S goes from -2 to +6. They both appear to be oxidized because they increased.
Please explain.
2)I think my problem is that I don't understand how you got the +2, +3, -2 and +6. I have looked at problems on the internet and see how they are oxidized or reduced when they write the numbers in the answers. I can follow that, but I don't see how they get the numbers in the first place. Please help me.
Dr. Bob222,
Ok, I'm starting to see how to get the oxidation numbers. However, since S goes from -2 to+6, does it also oxidize?
is it possible that both can oxidize? I thought one oxidized while the other reduced.
To determine whether Fe and S are being oxidized or reduced in this redox reaction, we need to compare the oxidation states of Fe and S before and after the reaction.
1. Start by assigning oxidation states to the elements in the reaction:
- In FeS, the oxidation state of Fe is +2, and the oxidation state of S is -2.
- In Fe2O3, the oxidation state of Fe is +3, and the oxidation state of O is -2.
- In H2SO4, the oxidation state of S is +6, and the oxidation state of O is -2.
2. Next, compare the oxidation states of Fe and S before and after the reaction:
- Fe goes from an oxidation state of +2 in FeS to +3 in Fe2O3. This means Fe has been oxidized (increased its oxidation state) in the reaction.
- S goes from an oxidation state of -2 in FeS to +6 in H2SO4. This means S has been oxidized (increased its oxidation state) in the reaction.
Therefore, the answers to your questions are:
- Fe is oxidized from +2 to +3.
- S is oxidized from -2 to +6.