Justify that the following reactions are redox reactions:

4 NH3(g) + 5 O2 (g) → 4NO(g) + 6H2O(g)

Let us write the oxidation number of each element involved in the given reaction as:


In NH3, N = -3 & H = + 1


In NO, N = + 2 & O = -2


In H2O, H = + 1 &O = -2


In O2, O = 0


Here, the oxidation number of N increases from -3 in NH3 to + 2 in NO. on the other hand, the O.N. of O2 decreases from 0 to -2 i.e. O2 is reduced.


Hence, the given reaction is a redox reaction.


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