Step-by-step explanation:
We have to find the oxidation state of N in each compound. The oxidation state of O is always -2 except from peroxides. The oxidation state of Na is +1 and the oxidation state of Cl is -1 in NH₄Cl.
a) HNO₃:
1 * (+1) + 1 * x + 3 * (-2) = 0
1 + x -6 = 0
x = +5 ----> oxidation state of N is +5.
b) NO:
1 * x + 1 * (-2) = 0
x = 2 ---> oxidation state of N is +2
c) N₂O:
2 * x + 1 * (-2) = 0
2 x - 2 = 0
x = 1 ----> oxidation state of N is +1
d) NH₄Cl:
1 * x + 4 * (+1) + 1 * (-1) = 0
x + 4 - 1 = 0
x = -3 ----> oxidation state of N is -3.
e) NaNO₂:
1 * (+1) + 1 * x + 2 * (-2) = 0
1 + x - 4 = 0
x = 3 ---> oxidation state of N is +3.
Answer: none of them.