Determine the oxidation numbers of all the elements in each of the following compounds.?

Question

one of them is a) Mn(ClO3)2 b) Fe2(CrO4)3 c) Hg Cr2O7 d) Co3(PO4)2 Can someone show me the steps to getting the oxidation numbers, i got stuck with this problem, this is just for me to practice, its not an assignment to turn in. The book didnt give good examples. The answers to this question were a) Mn:+2, Cl:+5, O: -2 b)Fe:+3, Cr:+6, O:-2 c) Hg: +2, Cr:+6 , O:-2 d) Co:+2, P: +5, O: -2

Answer 1

KevinR said it absolutely correct.

If you want it a little bit more easy:

(1) The metal ions always are positv oxidation numbers and this is the one of their load per ion.

(2) The oxigen always is -2 in such cases (exemptions are ozon or peroxides only)

(3) And the element in the anion has to carry the sum of oxidationnumbers of metal and oxigen, but with opposite sign.

Answer 2

The oxidation number, by definition, is a positive or negative number representing the effective charge of the individual atoms of a molecule. To figure out this problem, I would recommend finding a periodic table that contains the oxidation states for elements.

Here is one: http://www.standnes.no/chemix/periodictable/oxidation-numbers.gif .

Above the elements, there are specific numbers assigned. These numbers are the element's oxidation states. So, to work out Mn(ClO3)2: oxygen always has to have an oxidation state of -2. Since there are 6 oxygen atoms, the oxygen by itself takes a -12 charge. You then have to work with the 2 chlorines and the 1 manganese in an attempt to make the charge 0 (since the compound Mn(ClO3)2 has a zero charge). In the end, Mn would have a 2+ charge, Cl would have a 5+ charge resulting in an overall charge of 10+, and O would have a 2- charge resulting in an overall 12- charge. So, in total, 10+2-12=0.

Answer 3

Okay, well. H is +1, we know that. O is -2. The carbonate ion is CO3-2, so C is +4. Therefore, HCO3 is -1, and 2 of them makes Fe's charge +2. PO4 = -3. O = -2. P= +5. H= +1. HPO4 = +2. x3= -6. You have 2 Al's, so thats +3 each. There are also some trends on the table you just have to memorize, but remember, if the compound has no charge, it's 0. Work from the elements which have a stable charge to find variable charged ones.

Answer 4

well, since only metals can have different charges, you need to determine the charge of your anion(s) first. in a.) you have the chlorate ion which has a charge of -1. since there are two of them, the total negative charge is -2. this means that the managanese needs to have a +2 charge to make a neutral molecule. the Cl making the chlorate anion needs to add with 3 oxygens (always, always, ALWAYS a -2) to equal a total charge of -1. Three -2 charges equals -6 +5= -1, exactly what you want. ill let you go from there.

Answer 5

Try the site below. I had a great chem prof and her tutorials helped me a lot!

http://occc.edu/kmbailey/Chem1115Tutorials/Oxidation_Numbers.htm