Balancing a reaction

[Andrea_Torres]

In the test, I remember that they asked to balance the reaction but how do I do that?

[Tyler Angtuaco 1G]

Typically, you'll need to determine the oxidation and reduction half reactions. In each half reaction, balance all elements aside from H and O. Next, balance oxygens with water, then hydrogens with H+ ions. If the solution is alkaline/basic, balance H+ ions with OH- ions and combine them as water. Then, adjust the coefficients of each half reaction so that equal moles of electrons exist in each reaction. Find the overall balanced reaction by cancelling the moles of like species between the products/reactants of the oxidation reaction and the products/reactants of the reduction reaction.

[Anish Natarajan 4G]

Basically what you want to do is split the reaction into two half reactions; add water and hydrogen/OH ions to either side to balance molecules and add electrons to either side to make the charges balance out. Then multiply either reaction by a coefficient to make sure that the # of electrons on each side balances out and add the two balanced half reactions together

[Dan M -3E]

To balance the overall reaction, you have to separate into the redox half reactions, and use H+/OH- and H2O to balance those. After doing that, you just add the two reactions together and get the overall balanced reaction.

[Deena Doan 2F]

1. find the half-reactions
2. balance O
3. balance H
4. balance the charges by adding electrons

If you go through the textbook, it has a really helpful example that shows you step by step!

[Rohit Ghosh 4F]

You can balance O and H by adding water and protons in the case of an acidic solution, or OH- in the case of a basic solution.