Oxidation numbers, Electronegativity, & Naming Conventions

[el_alquimista]

Hey, everyone. I'm taking general chemistry right now and I'm having a bit of trouble getting down some of the stuff. In particular, how to find a compound's oxidation numbers (i.e. Na1+ Cl1-), especially for the more complicated compounds and also in remembering the naming conventions (carbon monoxide; CO).

If there's anyone who could give me an abbrieved, straight-forward explanation to ions, oxidation numbers and determining what they are for whatever compound and the naming conventions, I'd really appreciate it.

Thanks!


-El Alquimista

[octavia]

hi chemicoolers,im octa and im so inlove with chemistry,i gas my electronegativity is too muchso im a student at C.U.T and i study Biomedical Technology.

[KathChem82]

Hi Octa! I hope you could help me with my biochemistry queries. Especially about medical biochemistry. Tell me, are the major topics in your biochemistry class include the following? carbohydrates, nucleic acids, proteins, fats and lipids? Of course including metabolism. Can you tell me more about your major topics in your biochemistry class? Thanks.

[KathChem82]

how to find a compound's oxidation numbers

For the main group elements, their usual oxidation numbers are as follows:
Group 1 = +1
Group 2 = +2
Group 13 = +3
Group 14 = +4, sometimes -4
Group 15 = -3
Group 16 = -2
Group 17 = -1

Many of the transition metals have varying oxidation states. However there are rules to follow in assigning oxidation numbers to atoms, most especially if they are involved in bonding in a compound or molecule. The usual oxidation numbers of the main group elements is not always the case. Here are the rules.

1. Elements in their free, uncombined states have ON of 0. The ON of Na is 0. The ON of H2 is 0.

2. The ON a monatomic ion is its charge. Na+1 has an ON of +1.

3. The ON of oxygen is -2 except in peroxides (-1), superoxides (-1/2) and when paired with the more electronegative fluorine (+2).
In hydrogen peroxide, H2O2, ON of H is +1 and that of O is -1.
In potassium superoxide, KO2, the ON of K is +1 and that of O is -1/2.
In dioxygen difluoride, O2F2, the ON of F is -1 and that of O is +2.

4. The ON of hydrogen is +1 except in metal hydrides where its oxidation number is -1.
In sodium hydride, NaH, the ON of Na is +1 and that of H is -1.

5. The ON of fluorine is always -1. Other halogens such as chlorine, bromine, and iodine have have oxidation numbers of -1 in binary compounds, except when paired with more electronegative atoms.
In H-O-Cl, the ON of H is +1. O has -2 and Cl has +1.

6. Alkali metals (group 1) has oxidation numbers of +1.

7. Group 2 elements have +2.

8. The sum of the oxidation numbers of atoms in a compound or molecule is 0.

9. The sum of the oxidation numbers of atoms in a polyatomic ion is equal to the charge of the ion.


I hope this helps you.