#### Answer

+5
-3
+3
+3
+1

#### Work Step by Step

Recall the oxidation number of oxygen is always 2-. The oxidation number of Hydrogen is usually 1+. Therefore, Nitrogen's oxidation number must be +5.
The oxidation number of Hydrogen is usually 1+, unless in metal hydrides. Therefore, Nitrogen's oxidation number must be -3 , as the sum of all oxidation numbers must be equal to 0.
Recall the oxidation number of oxygen is always 2-. The oxidation number of Hydrogen is usually 1+. Therefore, Nitrogen's oxidation number must be +3, because the sum of all oxidation numbers in a compound must be equal to 0.
Recall the oxidation number of oxygen is always 2-. Therefore, Nitrogen's oxidation number must be +3. because the charge of ion is -1.
Recall the oxidation number of oxygen is always 2-. Therefore, Nitrogen's oxidation number must be +1 because the sum of the oxidation numbers must be 0.