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# Slightly confused by oxidation states/rules....

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1. So....

The sum of the oxidation states of all the atoms or ions in a neutral compound is zero.

The sum of the oxidation states of all the atoms in an ion is equal to the charge on the ion

Let us say then we have the ionic compound Hydrochloric acid.

HCL

H = 1 and CL = -1 so together they give us 0. That satisfies the 1st rule and would also satisfy the 2nd rule because the overall charge of the ion is 0?

Am I intrepreting/applying the rules correctly?
2. Yeah, it's right.

Could you work out the oxidation states of each atom in SO42-?
3. (Original post by Serine Soul)
Yeah, it's right.

Could you work out the oxidation states of each atom in SO42-?
SO42-

Formatting is key.
4. (Original post by alow)
SO42-

Formatting is key.
How do you do that?
5. (Original post by apronedsamurai)
So....

The sum of the oxidation states of all the atoms or ions in a neutral compound is zero.

The sum of the oxidation states of all the atoms in an ion is equal to the charge on the ion

Let us say then we have the ionic compound Hydrochloric acid.

HCL

H = 1 and CL = -1 so together they give us 0. That satisfies the 1st rule and would also satisfy the 2nd rule because the overall charge of the ion is 0?

Am I intrepreting/applying the rules correctly?
yuppp
but sometimes they change like
Fe in Fe2O3 has oxidation state of 3+
and in FeO it has an oxidation state of 2+
I think this is true for all transition metals.
6. (Original post by Serine Soul)
How do you do that?
click advanced and it'll come up with formatting options
clicking X2 = subscript and X2 = superscript
7. (Original post by z33)
click advanced and it'll come up with formatting options
clicking X2 = subscript and X2 = superscript
Ok, so I am getting a little confused by the half equations/oxidation numbers....

HNO3(aq) + H3AsO3 → NO(g) + H3AsO4(aq) + H2O(l)

HNO3(aq) H =1 N = 5 and O = -6 (Because 3x-2) and -6+5+1 =0

H3AsO3 H=3 (3x1) As=5 (Because group 5) and O = -6 (3x2)

But that means 3+-6+5=+2....? :|

Or should it be H =3 O =-6 and As =+3 to balance it out?
8. (Original post by z33)
click advanced and it'll come up with formatting options
clicking X2 = subscript and X2 = superscript
Ah I'm on the mobile browser version so the option isn't readily there. Thanks though!
9. (Original post by apronedsamurai)
Ok, so I am getting a little confused by the half equations/oxidation numbers....

HNO3(aq) + H3AsO3 → NO(g) + H3AsO4(aq) + H2O(l)
well in HNO3, the N has an oxidation state of +5, and then in the products (NO), N has an oxidation state of +2, so it's been reduced

the oxidation of As before is +3, and after it's +5 so it's been oxidised
10. (Original post by apronedsamurai)
Ok, so I am getting a little confused by the half equations/oxidation numbers....

HNO3(aq) + H3AsO3 → NO(g) + H3AsO4(aq) + H2O(l)
Identify which elements have been oxidised or reduced first
11. (Original post by Serine Soul)
Identify which elements have been oxidised or reduced first
I am working on the oxidation numbers to determine that.....
12. (Original post by z33)
well in HNO3, the N has an oxidation state of +5, and then in the products (NO), N has an oxidation state of +2, so it's been reduced

the oxidation of As before is +3, and after it's +5 so it's been oxidised
Nah, I knew that Z33, I was just making sure I had gotten the formatting right, and had then amended my post
13. (Original post by z33)
well in HNO3, the N has an oxidation state of +5, and then in the products (NO), N has an oxidation state of +2, so it's been reduced

the oxidation of As before is +3, and after it's +5 so it's been oxidised
HNO3(aq) + H3AsO3 → NO(g) + H3AsO4(aq) + H2O(l)

HNO3(aq) H =1 N = 5 and O = -6 (Because 3x-2) and -6+5+1 =0

H3AsO3 H=3 (3x1) As=5 (Because group 5) and O = -6 (3x2)

But that means 3+-6+5=+2....? :|

Or should it be H =3 O =-6 and As =+3 to balance it out?
14. (Original post by apronedsamurai)
Nah, I knew that Z33, I was just making sure I had gotten the formatting right, and had then amended my post
oooooooooooooooooooooooh oops
15. (Original post by apronedsamurai)
I am working on the oxidation numbers to determine that.....
As a general rule of thumb O = -2, H = +1, with exceptions of course

Can you work that out now?
16. (Original post by z33)
oooooooooooooooooooooooh oops
Can you look over my new post please
17. (Original post by apronedsamurai)
HNO3(aq) + H3AsO3 → NO(g) + H3AsO4(aq) + H2O(l)

HNO3(aq) H =1 N = 5 and O = -6 (Because 3x-2) and -6+5+1 =0

H3AsO3 H=3 (3x1) As=5 (Because group 5) and O = -6 (3x2)

But that means 3+-6+5=+2....? :|

Or should it be H =3 O =-6 and As =+3 to balance it out?
yeah it should be H = +3 and O = -6 because H is always +1 and O is always -2 so you work with them instead of As
18. (Original post by apronedsamurai)

Or should it be H =3 O =-6 and As =+3 to balance it out?
That's correct
19. (Original post by z33)
yeah it should be H = +3 and O = -6 because H is always +1 and O is always -2 so you work with them instead of As
PRSOM
20. (Original post by apronedsamurai)
PRSOM

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