Separate this redox reaction into its component half-reactions.
O2 + 2Mg----> 2MgO
O2 + 4e ==> 2O^2-
Mg ==> Mg^2+ + 2e
To separate the given redox reaction into half-reactions, you need to identify the oxidation and reduction half-reactions separately. Here's how you can do it:
Step 1: Assign oxidation numbers to each element in both the reactants and the products. The oxidation number is a positive or negative number that represents the charge an atom carries when it gains or loses electrons.
In this reaction, oxygen (O2) is not combined with any other element, so its oxidation number is 0. The oxidation number of magnesium (Mg) in the reactant side is 0, and in the product side, it is +2 in MgO.
Step 2: Determine the change in oxidation number for each element by comparing the oxidation numbers in the reactants and the products.
For oxygen, the oxidation number changes from 0 in O2 to -2 in MgO, indicating reduction (gaining electrons).
For magnesium, the oxidation number changes from 0 in Mg to +2 in MgO, indicating oxidation (losing electrons).
Step 3: Write the oxidation and reduction half-reactions using the elements involved and the changes in oxidation numbers.
Oxidation half-reaction:
Mg --> Mg^2+ + 2e^-
Reduction half-reaction:
O2 + 4e^- --> 2O^2-
Note: To balance the number of electrons, you might need to multiply the half-reactions to make the electrons equal in both.
So, the half-reactions for the given redox reaction are:
Oxidation: Mg --> Mg^2+ + 2e^-
Reduction: O2 + 4e^- --> 2O^2-
To separate the redox reaction into its component half-reactions, we need to identify the oxidation and reduction half-reactions.
Let's start with the given reaction:
O2 + 2Mg ----> 2MgO
Step 1: Identify the oxidation state of each element in the reaction.
In O2, oxygen has an oxidation state of 0 since it is in its elemental form.
In MgO, oxygen has an oxidation state of -2, and magnesium has an oxidation state of +2.
Step 2: Identify the atoms that are undergoing oxidation and reduction.
In the given reaction, magnesium (Mg) is undergoing oxidation and oxygen (O2) is undergoing reduction.
Step 3: Write the half-reactions for oxidation and reduction.
Oxidation half-reaction: Mg ----> Mg^2+ + 2e^-
Reduction half-reaction: O2 + 4e^- ----> 2O^2-
In the oxidation half-reaction, magnesium (Mg) is oxidized to Mg^2+ by losing 2 electrons (e^-).
In the reduction half-reaction, oxygen (O2) gains 4 electrons (4e^-) to form 2 oxide ions (O^2-).
Therefore, the component half-reactions for the given redox reaction O2 + 2Mg ----> 2MgO are:
Oxidation half-reaction: Mg ----> Mg^2+ + 2e^-
Reduction half-reaction: O2 + 4e^- ----> 2O^2-