valencies of carbonates etc (1 Viewer)

[lilkatie]

hey guys
i really need one of those sheets that has the valencies of carbonates sulphates etc
i got through prelim without knowing them but i need them for oxidation states
so how do i know the valencies of them
thanks in advance

 

[Dreamerish*~]

CO₃^2- carbonate

SO₄^2- sulphate

SO₃^2- sulphite

SO^2- sulphur dioxide

S^2- sulfide

NO₃^- nitrate

NO₂^- nitrite

PO₄^3- phosphate

this's from memory. i'm not too sure that they're all right.

 

[Dreamerish*~]

haha it's not too hard

just remember : C-2, S-2, P-4, N-1

 

[lilkatie]

hey hey thats cool tah

 

[Casmira]

 

[Emma-Jayde]

Remember the 'ates' like this, this way also helps you with the formulas:

Naughty Children Smoke Pot- (hehe or Nice Children Smell Purfume, as my chem teacher would have us believe!)

NO₃^1- CO₃^2- SO₄^2- PO₄^3-




Write your NO CO SO PO in a line. Start at the top left with NO, and write 1- above it. Then work across using the pattern of one 1, two 2's, three 3's and finally the 4's. When you get to the end of the row, PO^3- move back to NO and write a number 3 at the bottom. continue till you get to PO₄.
The valency is the number at the top, if you didn't know already. The 'ites' for these 4 have the same valency as the 'ates', they just have one less oxygen.
Can't really help you with remembering the others

 

[jamesy_1988]

haha it's not too hard

just remember : C-2, S-2, P-4, N-1

These are the correct oxidation numbers

Carbon is nearly always has a oxidation number of +/-4

Nitrogen usually has a oxidation number of -3 but can change

Oxygen has a oxidation number of -2 in usually but has an oxidation number of -1 in peroxides or superoxides (potassium oxide)

Sulfur can have an oxidation number of -2, -4, -6, -8, and I think that it can have
-16 as well, but I'm not sure on this one.

Halides usually have an oxidation number of -1 though this can change

If there are any more that you need to know, just drop me a line

Jamesy