N2H4
H3CO2H
C2H2O4
This should be the right answer, let me know if its not so i can know for future.
Concepts to understand before solving:
-Oxygen is ALWAYS reduced
-OIL- Oxidation Is Loss of electrons
-RIG- Reduction Is Gain of electrons
-the element that is oxidized is the reducing agent
-the element that is reduced is the oxidizing agent
A. 2H2 + O2 —> 2H2O
O is reduced, making it the oxidizing agent
H is oxidized, making it the reducing agent
B. 2KNO3 —> 2KNO2 + O2
O is reduced, making it the oxidizing agent
KNO is oxidized, making it the reducing agent
Is this what you wanted if not I can provide with more info: reduction is the part of an Oxidation–Reduction reaction in which there is a gain of electrons by a species or a decrease of the oxidation number of an atom. So C, there is no change so NOT a reduced state. In A the oxidation number has to go up by 2 for oxygen's oxidation number is always -2, so the leaves B, were the bond with the hydrogen atom would donate an electron, thus reducing X