What is the oxidizing and reducing agent in the following reaction: Zn(s) + 2H+(aq) ----> Zn2+(aq) + H2(g)
The term "redox equation" comes from two concepts, of reduction and oxidation. It can be explained in simple terms:
Oxidation: the loss of electrons or an increase in the oxidation state by an atom, molecule, or ion.
Reduction: the gain of electrons or a decrease in oxidation state by an atom, molecule, or ion
In the equation, zinc is losing 2 electrons; it is being oxidized. The hydrogen is gaining 2 electrons, so it is being reduced. Now here is where it gets tricky! The atom being oxidized is the "reducing agent", because it is increasing the oxidation state of the other atom; that would be the zinc (Zn). The atom being reduced is the "oxidizing agent", because it is causing a decrease in the oxidation state of the other atom; that would be the hydrogen.