What element is undergoing oxidation (if any) in the following reaction?
CH4(g) + 2 O2(g) �¨ CO2(g) + 2 H2O(g)
Carbon is the element undergoing oxidation
Well, let's analyze the reaction, shall we? In the reactant side, we have CH4, which is methane, and O2, which is oxygen. And on the product side, we have CO2, which is carbon dioxide, and H2O, which is water.
Now, oxidation is the loss of electrons, so we need to look for the atom that is losing electrons. In the reactants, we see that the carbon atom in methane has an oxidation state of -4 (each hydrogen atom has an oxidation state of +1). In the products, the carbon atom in carbon dioxide has an oxidation state of +4 (each oxygen atom has an oxidation state of -2).
Therefore, the carbon atom in methane undergoes oxidation. It loses hydrogen atoms and gains oxygen atoms, resulting in a more positive oxidation state. Poor little carbon, it's going through a rough time in this reaction!
To determine which element is undergoing oxidation in a chemical reaction, you need to compare the oxidation states of the elements in the reactants and products.
In the reaction: CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(g)
Let's assign oxidation states to the various elements:
Oxidation state of H in CH4: +1
Oxidation state of C in CH4: -4
Oxidation state of O in O2: 0
Oxidation state of C in CO2: +4
Oxidation state of O in CO2: -2
Oxidation state of H in H2O: +1
Oxidation state of O in H2O: -2
From the above assignments, we can see that the oxidation state of carbon (C) in CH4 (methane) has changed from -4 to +4 in CO2 (carbon dioxide). In other words, the carbon atom has lost electrons and has been oxidized.
Therefore, carbon (C) is the element undergoing oxidation in the given reaction.
Find the element that is losing electrons. Here is a hint.
C has an oxidation state of -4 on the left; +4 on the right.
H is +1 on both sides.
O is zero on the left and =2 on the right.
For C and O, one lost electrons and one gained electrons.