Question

How many moles of electrons are required to reduce one mole of nitrogen gas (N2) to two moles of nitrogen ions (N3-)?

Answer 1

Start by writing the atoms balance:


`N_(2) -\ \textgreater \ 2N^(3-)`

Now, determine the change of oxidation states:
`N_(2)` has oxidation state 0, so each N has to gain 3 electrons to become
`N^(3-)`.

That, means that you need 6 electrons to balance the charges, resulting in:


`N_(2) + 6 e^(-) -\ \textgreater \ 2 N_(3-)`

And the answer is 6 mole of electrons.