Question

Select the correct decreasing order of the oxidation state of nitrogen in the following options:

• A. $HN{O}_3,NO,N{H}_{4}Cl,N_2$
• B. $HN{O}_3,NO,N_2,N{H}_{4}Cl$
• C. $HN{O}_3,N{H}_{4}Cl,NO,N_2$
• D. $NO,HN{O}_3,N{H}_{4}Cl,N_2$

Answer 1

The correct option is B $HN{O}_3,NO,N_2,N{H}_{4}Cl$

Oxidation state of Nitrogen in different compounds is as follows:
Assume Nitrogen has O.S of x.
In $HN{O}_3$
O.S of H is +1 and O is -2
equating: +1 +x + 3*(-2) = 0
So x = +5
In NO,
x + (-2) = 0: x = +2
In $N_2$, being a neutral molecule it has 0 oxidation state
In $N{H}_{4}Cl$
x + 4*(+1) + (-1) = 0
hence x = -3
Order in decreasing O.S is
$HN{O}_3>NO>N_2>N{H}_{4}Cl$