I'm confused with this question as I don't understand how to write the reactions. Here is the question if you could please help me with this question or just even give me an example on how to do it. I would really appreciate it. Thank you.
Write the oxidation and reduction half reactions for the following full reaction.
AgBr + Na ==> Ag + NaBr
I just don't understand how to write the oxidation and reduction half reactions, I only know how to do full reactions.
First you separate the full reaction which you have written into the two half reactions. To do that, follow these steps.
1. Write the oxidation state of each element/ion above it. For example, above Ag in AgBr you place a +1. Br in AgBr is -1. Na is zero (all elements are zero. Ag on the right is zero, Na in NaBr is +2 and Br in NaBr is -1.
2. What changed?
a. Ag changed from +1 on the left to zero on the right. So the half reaction for that is Ag^+1 + e ==> Ag.
b. Na changed from zero on the left to +1 on the right. So the half reaction for that is Na ==> Na^+1 + e
c. note that Br didn't change. It was -1 on the left and it is -1 on the right.
d. Then label each half reaction as oxidation or reduction. To do that you simply remember the definitions.
Oxidation is the loss of electrons (have you heard the mnemonic---Leo the lion goes Grrrrr---Leo tells you. Loss Electrons Oxidation. Of course reduction is the opposite; i.e., gain of electrons is reduction.
The Ag half reaction is reduction (because it ADDED an electron). The Na half reaction is oxidation (because it LOST an electron.)
Here is a site to help you do oxidation states if you are unsure about them.
http://www.chemteam.info/Redox/Redox-Rules.html
Na in NaBr is +1 (not +2)
Thank you for your help, especially the Leo the lion, thank you, I couldn't say it enough. You have helped me so much. Thank you.
I'd be happy to help you with this question and explain how to write oxidation and reduction half-reactions!
When writing the oxidation and reduction half-reactions, it's important to first identify which species is getting oxidized and which one is getting reduced. In oxidation-reduction reactions, electrons are transferred from one species to another.
To write the half-reactions, follow these steps:
1. Start by identifying the atoms that are changing their oxidation states in the reaction. In this case, we can see that Ag is going from an oxidation state of 0 to +1, and Na is going from an oxidation state of +1 to 0.
2. Write the half-reactions separately for the oxidation and reduction processes, keeping in mind that oxidation is the loss of electrons and reduction is the gain of electrons.
The oxidation half-reaction involves the species that is getting oxidized, which is AgBr in this case. Since Ag is going from an oxidation state of 0 to +1, it means it's losing one electron. Therefore, the oxidation half-reaction for AgBr would be:
AgBr → Ag + 1e-
The reduction half-reaction involves the species that is getting reduced, which is Na in this case. Since Na is going from an oxidation state of +1 to 0, it means it's gaining one electron. Therefore, the reduction half-reaction for Na would be:
Na+ + 1e- → Na
These individual half-reactions show the species losing or gaining electrons, representing the oxidation and reduction processes.
To balance the charges and the number of atoms in the half-reactions, you may need to add coefficients and adjust the coefficients accordingly.
Keep in mind that the electrons transferred in the oxidation half-reaction must be equal to the electrons gained in the reduction half-reaction to balance the overall reaction.
I hope this explanation helps you understand how to write oxidation and reduction half-reactions! If you have any further questions or need more examples, feel free to ask.