Oxidation number of ..?
all elements there
K -> Group I metal. Either 0, or +1. Here, it's an ion. So, what is the oxidation number of K?
Btw, I think it's K2Cr2O7 on the left?
yes, there is a typo :)
Okay. What have you got for K?
could you check my answers?
I'll just post it :)
Yup. For both sides, there is no oxidation number change for K. So, K on both sides are +1. Sure :)
I'll just answer it :)
Isn't it that if the subscript of O is greater than 2, it will have an oxidation number of -2 ?
O has an oxidation number of -2 - You're right! :)
but if "O" only it will have -1 and O2 it will have 0?
No, not really. O is in group 6, it need 2 more electrons. So, usually, its oxidation number is -2 when it is bonded to other atoms. If it is an element (i.e. O2), its oxidation number is 0 as element in its own form. But remember, it's just 'usually' when its oxidation number is of -2. There are some exceptions. For instance, if I remember correctly, O in F2O is +2 since F is a more electronegative element and it has an oxidation number of -1. Since there are two F, oxidation number of O has to be +2 in order to get a net oxidation number of the compound equal to zero.
ohh, thanks for the info. Here are my answers :) K2(+1)Cr2(+6)O7(-2) + S8(0) ----> K2(+1)O(-2) + Cr2(+3)O3(-2) + S(0)O2(0) The oxidation number is enclosed by parenthesis.
Is it correct ?
Almost. S(0)O2(0) <- not correct (for both)
K2(+1)Cr2(+6)O7(-2) + S8(0) ----> K2(+1)O(-2) + Cr2(+3)O3(-2) + S(-2)O2(+1)
I made the oxidation number of O2 the unknown. Is it correct now?
Not really. For SO2, O is -2 (you can take a look at O first as it is more electronegative than S!) O2 is NOT an element in this case, so O doesn't have a oxidation number of 0!
K2(+1)Cr2(+6)O7(-2) + S8(0) ----> K2(+1)O(-2) + Cr2(+3)O3(-2) + S(+4)O2(-2) I think this is correct already :)
I'll say something. I'll just fix the laptop :)
please wait :)
Take your time!
Whew! The battery almost got dead. It keeps on saying plugged in, not charging.
So it means, If you have a molecule with an oxygen,to find the oxidation number of the elements in it. You will identify first the more electronegative element and made the charge of it equal to its oxidation number. Then make the oxidation number of the other element the unknown.
you will solve for the unknown oxidation number
Hmm.. you can say so. But when you consider electronegativity of the element, that would be talking about the group V - group VII For metal, it usually has positive oxidation number. If I remember correctly, for group I metal, when it does not exist in element state, it should be of an oxidation number of +1, and looks like it works for most of the group II metal too. But for transition metals, that's another case...
One little practice for you (if you want one lol) Find the oxidation number of H, O and Cl in the compound HOCl.
I hope it is correct. :)
There are three definitions....
is it the loss of electrons and reactions directly with O2 ?
transfer of electrons?
Definition of oxidation: 1. addition of oxygen to a substance 2. a process in which a substance loses electrons 3. a process in which the oxidation number of an element in a substance increases.
and reduction is the opposite of that?
In my notes it says below oxidation it says: +O -H What does "H" have to do with oxidation and reduction ?
idk I just saw in my notes. I was late during our class so I didn't know what is H there
Anyway, thank you very much in your time and effort helping me. :)
You're welcome.. Sorry that I couldn't help :(
It's alright you helped me a lot. :)