You are Here: Home

# hydrogen peroxide redox reaction Watch

1. Hey, I'm a bit confused on the redox reactions in hydrogen peroxide

2 H2O2 ----> 2 H2O + O2

Thats the overall reaction

Am I correct in saying that

Oxygen's oxidation numbers
-1 in hydrogen peroxide
-2 in water
0 in oxygen

and that hydrogen stays the same at +1

I was wondering how the half equations looked in this reaction?

would...

0-1 + e ---> O-2
0-1 -----> O + e

be correct? it doesn't seem right to me

Many thanks
2. Yes, you are right about those oxidation numbers for oxygen.

The half equations need to be written with the starting species going to the final species with the electrons either being added or produced. Like this

see if you can work out the half reactions now...
3. (Original post by Plato's Trousers)
Yes, you are right about those oxidation numbers for oxygen.

The half equations need to be written with the starting species going to the final species with the electrons either being added or produced. Like this

see if you can work out the half reactions now...
Thanks Is it not just...

Those half equations don't seem to make complete sense to me in context of the overall decomposition reaction - but they are the only ones that I can make workable.
4. ok, so this is called a disproportionation reaction. The initial species is both oxidised (to form oxygen) and reduced (to form water) at the same time.

So you have

oxidation

and

reduction

in the first, oxygen goes from -1 to 0 and in the second it goes from -1 to -2

you see how adding both equations together gives you the overall one?
5. (Original post by Plato's Trousers)
ok, so this is called a disproportionation reaction. The initial species is both oxidised (to form oxygen) and reduced (to form water) at the same time.

So you have

oxidation

and

reduction

in the first, oxygen goes from -1 to 0 and in the second it goes from -1 to -2

you see how adding both equations together gives you the overall one?
That's fantastic, thankyou very much for your help. One lat quick question would it be correct to say half the oxygen is being oxidised and half reduced - or is that a simplistic way of wording it?
6. (Original post by Organ)
That's fantastic, thankyou very much for your help. One lat quick question would it be correct to say half the oxygen is being oxidised and half reduced - or is that a simplistic way of wording it?
yes. you can imagine that for every two peroxides, one is being oxidised and is supplying the electrons to reduce the other one.
7. I know this questions was asked awhile ago but i was having problems with this myself, I wanted to add that i found it easier to understand if i though about it as 2 oxygens giving up a hydrogen atom and the other two getting an extra hydrogen atom i.e Yh so i might make a phew chemists angry doing it this way, but for me chemical equations can be abit difficult to understand without breaking it down into the maths that im use to. Also if you think about each hydrogen atom as carrying an electron with it that will be donated to the oxygen this can apply to question.

The OP probably doesn't need help with this anymore so i though it could help anyone who is having difficulty understanding the logic beind this equation as i did.

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: March 19, 2011
Today on TSR

### Oxford interview invitations

When is yours coming?

### Highest poster before midnight WINS £30!

Discussions on TSR

• Latest
• ## See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• Poll
Discussions on TSR

• Latest
• ## See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.