Balancing Redox

[Joanna Huang]

When balancing redox, how does one find out how many electrons to put on each side of the equation?

[Hannah Alltucker 3L]

You can check by how much the charge of each half changes when it is either oxidized or reduced based on what you are given. They normally give us some sense of how many e- are transferred by how much the charge grows or lesses (so +2 -> 0 charge means 2 electrons are being transferred). Then, for a final answer on how many e- are used in a reaction, we want the number of electrons on each side of the reaction arrow to match, so we can multiply the halves separately until we have the same whole number of e- on both sides, and this will become our final number of e- transferred.

[Francesca_Borchardt_2D]

To find this, look at the charges on each side of the equation. Say if one side has a neutral charge of zero, and the others charge is 4+, you would add 4 electrons to the zero side to balance the equation and make it 4+. Hope this helps!

[Sera Aintablian 2E]

You would have to calculate the charges of each element in each compound on both sides to see where the electrons would be transferred! ( i.e. which side they would be on to equal the other side). I used this chart from sapling throughout the homework which helped! https://sites.google.com/site/chempendix/oxidation

[Sabine Salvucci 2E]

To find out how many electrons to put on each side of the equation, you first have to calculate the charges on each side of the equation after you have otherwise balanced it. Then just add electrons so the charges on both sides match. For example, if the charge of the reactants is +2 and the charge of the products is -1, you would add 3 electrons to the reactants. Hope this helps!

[Jeremy Wei 2C]

You can calculate the number of electrons to put on each side by finding the charges present on each side, and you would add electrons to each side accordingly to balance the charge for the overall equation. Hope this helps!

[Brianna Chen 3F]

First, you want to balance the elements in the equation (ex. using H2O or OH-) and then from there you would look at the overall charge of each side. Whichever side has the more positive overall charge, you would add electrons to it to equal the opposite side.

[Adrienne Yuh 2B]

I usually look at the oxidation numbers and see the total number of "charges" that can be balanced with electrons.

[Akemi Karamitsos 1E]

After identifying the half reaction and balancing all elements, you can identify the total oxidation charge on both sides of each half reaction. Add the appropriate number of electrons to the side that has a more positive charge so that both sides become equal. Do this for both half reactions. Then ensure the number of electrons for both half reactions is the same.

[Liam Bertrand 3]

Use the charges given and the oxidation numbers to figure out how many e-'s to add

[Will Skinner]

First you balance the half reaction. Then find the net charge on both sides and add the correct amount of e- on one side in order to balance the charge.

[Chudi Onyedika 3A]

Look at the charges on each side and apply enough electrons to a side to make the charges on both sides equivalent.

[Abhinav Behl 3G]

In order to figure out how many electrons to add to a half-reaction, simply calculate the total charges on both the reactant side and product side. If you notice that one side is more positive than the other side, then you would add electrons to this side in order to make the charges on both sides equal.

[jessicaosuna_1F]

I look at the difference in oxidation number for each half-reaction individually and then find the least common multiple to get the reaction balanced.

[Daniela Santana 2L]

Hi! I usually first identify which half-reaction is the reduction one and which is the oxidation one. I also write down the oxidation numbers of each side of each half-reaction. Once the half reaction is all balanced and you're deciding how many electrons and where to put them, I revisit the half-reactions original oxidation numbers. The change in oxidation number is usually the amount of electrons needed. When dealing with the reduction half-reaction you usually put it on the left side of the reaction. For oxidation half-reactions you usually put it on the right side.

[Colin Squire 3B]

By looking at the total charge of the reactants to the total charge of the products, we can determine how many electrons were transferred in order to find the "n" value. It is also important to note that in some cases (like acidic and basic solutions) water, H+ and OH- can change the overall charge.

[Brian Nguyen 2I]

Take a look at the half reactions and balance out the electrons to make sure that there is the same amount of electrons on both sides of the redox equation.