7-4 Identify atoms oxidized or reduced based on oxidation numbers

7-4-1. What is reduced in the following reaction?
Cu(s) + HNO3(aq) = NO(g) + Cu(NO3)2(aq) + H2O(l)
A. Cu, B. H, C. N, D. O



7-4-2. In the reaction: 2 BaO2(s) = 2 BaO(s) + O2(g)
Which is false?
A. BaO2 is oxidized, B. BaO2 is reduced
C. Ba is oxidized, D. O is oxidized
E. O is reduced



7-4-JJW. In the reaction, 2 Fe2O3 + 3 C → 4 Fe + 3 CO2 which element is oxidized?
A. Fe, B. O, C. C


7-4-ALD. Identify the element that is oxidized in the chemical reaction given below:
Mn(s) + Fe(NO3)3(aq) → Mn(NO3)2(aq) + Fe(s)

A. Mn, B. Fe, C. N, D. O