oxidation numbers question?

[thatdumbstudent]

Hi there! Referring to the equation shown in the image, I have to find the oxidation number of nitrogen before the reaction, which is +5 which I understand, however after the reaction is +4 and I don't understand why it's that.. could someone explain? thanks :-)

[Evolio]

Hi there! Referring to the equation shown in the image, I have to find the oxidation number of nitrogen before the reaction, which is +5 which I understand, however after the reaction is +4 and I don't understand why it's that.. could someone explain? thanks :-)

Hello.
So, I would use the 2NO2(g) as that looks the simplest and easiest to find the oxidation number of N. The oxidation number of Oxygen is -2 and there are 4 oxygens here. So, 2N+4O=0. Substitute the O=-2. 2N-8=0. 2N=8. Thus, N=+4.

In this case, where N is present in both compounds produced, I would use the compound that is the simplest and the one where there is sufficient information to find the value of the N.

[thatdumbstudent]

Hello.
So, I would use the 2NO2(g) as that looks the simplest and easiest to find the oxidation number of N. The oxidation number of Oxygen is -2 and there are 4 oxygens here. So, 2N+4O=0. Substitute the O=-2. 2N-8=0. 2N=8. Thus, N=+4.

In this case, where N is present in both compounds produced, I would use the compound that is the simplest and the one where there is sufficient information to find the value of the N.

I’ve actually been ignoring 2NO2 the whole time, it is much simpler and I get it now, thank you!! 😁