oxidation numbers

[Kylie McCauley 1D]

hi,

What are oxidation numbers, how do we calculate them, and will we have to know how to calculate/apply them to the midterm?

[Meghan Krushena 2E]

Oxidation numbers, I believe, are the total number of electrons that an atom either gains or loses when forming a bond with another atom

[Charlie Russell 2L]

Oxidation numbers, also called oxidation states, are the total number of electrons that an atom either gains or loses in order to form a chemical bond with another atom.

An oxidation number can be assigned to a given element or compound by following the following rules:

- The oxidation number of a free element (a chemical element that is not combined with or chemically bonded to other elements like O₂) is always 0.

- The oxidation number of a monatomic ion (such as K⁺ or O^2-) equals the charge of the ion.

- Fluorine in compounds is always assigned an oxidation number of -1.

- The alkali metals (group I) always have an oxidation number of +1.

- The alkaline earth metals (group II) are always assigned an oxidation number of +2.

- Oxygen almost always has an oxidation number of -2, except in peroxides (H₂O₂) where it is -1 and in compounds with fluorine (OF₂) where it is +2.

- Hydrogen has an oxidation number of +1 when combined with non-metals, but it has an oxidation number of -1 when combined with metals.

The algebraic sum of the oxidation numbers of elements in a compound is zero.
The algebraic sum of the oxidation states in an ion is equal to the charge on the ion.

They relate to bonding and charges and this unit is primarily bonding, and my TA said they are fair game on the midterm.

Hope this helps!

(look up a picture or video on oxidation numbers online!)

[Gustavo_Chavez_1K]

The oxidation number refers to the number of electrons gained or lost, so it could be a positive, negative, or zero. Basically it helps keep track of electrons in an atom. There a couple of different rules when determining oxidation numbers, for example, the oxidation number of an atom is zero in a neutral substance that contains atoms of only one element and the oxidation number of simple ions is equal to the charge of the ion.

[Kandyce Lance 3E]

Oxidation numbers, also called oxidation states, are the total number of electrons that an atom either gains or loses in order to form a chemical bond with another atom.

An oxidation number can be assigned to a given element or compound by following the following rules:

- The oxidation number of a free element (a chemical element that is not combined with or chemically bonded to other elements like O₂) is always 0.

- The oxidation number of a monatomic ion (such as K⁺ or O^2-) equals the charge of the ion.

- Fluorine in compounds is always assigned an oxidation number of -1.

- The alkali metals (group I) always have an oxidation number of +1.

- The alkaline earth metals (group II) are always assigned an oxidation number of +2.

- Oxygen almost always has an oxidation number of -2, except in peroxides (H₂O₂) where it is -1 and in compounds with fluorine (OF₂) where it is +2.

- Hydrogen has an oxidation number of +1 when combined with non-metals, but it has an oxidation number of -1 when combined with metals.

The algebraic sum of the oxidation numbers of elements in a compound is zero.
The algebraic sum of the oxidation states in an ion is equal to the charge on the ion.

They relate to bonding and charges and this unit is primarily bonding, and my TA said they are fair game on the midterm.

Hope this helps!

(look up a picture or video on oxidation numbers online!)

This is so incredibly helpful thank you!! I was struggling with oxidation numbers before and even watched a few videos but nothing was clearing up my confusion. Think I'm starting to get the hang of it now thanks again!