[dawson169]

I'm going nuts. Well here is the question I'm given:

  Under acidic conditions, hydrocarbons may be made to react with nitric acid via the (unbalanced) redox reaction: C₄H₁₀ + HNO₃ --->  NO₂ + CO₂  Balance the reaction.

[Ans.: C4H10 + 26HNO3 ---> 4CO2 + 26NO2 + 18H2O]

Okay now heres my question ... I did the problem by making the NO₂ a negative 1 which is the only way I have seen NO₂. I did the problem making the NO₂ netrual and I got the anwer right. Why is it netural in this problem cause I thought its usually a negative 1 ?

[Borek]

NO₂ is a gas, HNO₂ is a nitrous acid which dissociates into H⁺ and NO₂^-.

[AWK]

NO2 is a molecule, not an anion.

You can solve this reaction, even without balancing electrons.
2HNO3 = H2O + N2O5
You can treat N2O5 as molecule giving 1 oxygen atom for oxidation
N2O5 = 2NO2 + O (atom)
For C4H10 you need 4 x 2  + 10 x 1/2 oxygen atoms - these are equivalent to 13 N2O5 or  26 HNO3, and produce 4CO2, 26NO2 and (13+5)H2O