oxidation states

[Mariane Sanchez 1E]

How do you find the oxidation state of an element/molecule? Is it just something you memorize?

[Ethan Vuong 3G]

You use the periodic table and count the number of electrons needed to gain or lose to be the same as the noble gases.

[Jessica Nunez 1I]

An example of finding the oxidation state could be MnO4-. We know the overall charge of MnO4- is -1 and oxygen as O4 has a charge of -8, so we only need to find the charge of Mn.

x + 4(-2) = -1

x-8 = -1

x = +7

The charge of Mn is +7.

[Karen Ung 2H]

Additoinally, there are a few rules you can follow when determining oxidation states. H will always have the oxidation state of +1. O will have the oxidation state of -2, except in H2O2, when oxygen's oxidation state is -1. The charges of elements are the oxidation state numbers. For example, Cr 3+ has an oxidation number of 3+.

[soniatripathy]

there are a few basic rules that you are supposed to memorize for assigning oxidation numbers. I found that this video is really helpful for learning them: https://www.youtube.com/watch?v=-a2ckxhfDjQ
Hopefully this video helps!