oxidation-reduction?

Question

FeS(s) + 3NO3-(aq) + 4H+(aq)----->3NO(g) + SO42-(aq) + Fe3+(aq) + 2H2O(l)

-what is reduced and what is oxidized??

Answer 1

An element is oxidized when it's oxidation number increases - looses electrons - and is reduced when it's oxidizing number decreases - gains electrons. So, in this case:

Fe is oxidized because it's oxid. num. increases from +2 (in FeS) to +3.
S is also oxidized because it's oxid. num. increases from -2 (in FeS) to +6 (in SO42-).

N is reduced because it's oxid. num. decreases from +5 (in NO3-) to +2 (in NO).

We can also say that Fe and S are the reducing elements - or that FeS is the reducing substance - and N is the oxidizing element - or NO3- is the oxidizing substance.

Answer 2

No not all reaction are redox. Reaction between metals and non-metals are only redox reaction Redox means reduction and oxidation, which is the gain or loss of electron forming and ionic bond. Oxidation=loss of electrons Reduction= gain of electrons e.g.a rection between a nonmetal and metal is known as redox reaction. Metals are oxidized Non-metasl are reduced There is change in oxidation state. However in non-metals there is a covalent bonding, electrons are not gained or lost but instead is shared. This is not a redox reaction. Remember : Redox must involve metals. Metals are resposible for any redox reaction

Answer 3

Remember with these, LEO says GER for Loses Electron is Oxidation and Gains Electron is Reduction.

It looks like the NO is oxidized, so is the Fe, the hydrogen is reduced to the water, and the sulfer is just a complex ion.