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Topic: Oxidation number  (Read 4009 times)

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Offline peterschmidt3943

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Oxidation number
« on: February 14, 2018, 03:17:53 PM »
Hello,

I have a few questions regarding the topic oxidation number
What are the oxidation numbers of following molecules?

O2·− => in my book it says -1/2, but why???
OH·
OH-
H2O

IO3-
IO4-


C2H6 => H=6 C=-6
C2H5Cl
C2H5OF 
C2H4O2

to the last three: I did not know what to write since I have to include the inductive effect, isnt it? How do I identify the oxidation number then?
I need quick help on this one please, it is exam relevant for my medical studies..

Offline Borek

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Re: Oxidation number
« Reply #1 on: February 14, 2018, 04:25:33 PM »
What are the oxidation numbers of following molecules?

Oxidation number is a property of an atom, not of a molecule.
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Offline peterschmidt3943

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Re: Oxidation number
« Reply #2 on: February 14, 2018, 04:29:37 PM »
atom*

Offline Borek

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Re: Oxidation number
« Reply #3 on: February 14, 2018, 04:44:53 PM »
What rules do you know? Just apply them, most of these molecules are trivial to analyze.
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Offline peterschmidt3943

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Re: Oxidation number
« Reply #4 on: February 14, 2018, 04:49:31 PM »

O2·− =>  -1/2, but why???
OH· => I dont know..
OH- O= -2  H=2
H2O  => O=-2  H =2

IO3-  O= -5   I = 5
IO4-  O=-7  I =7


C2H6 => H=6 C=-6
C2H5Cl   => H=5   Cl=-1   C= -4
C2H5OF  =>  H= 5  O=-2   F=-1  C=-2
C2H4O2  =>  O=0 H=4  C= -4


everything alright ?


Offline Borek

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Re: Oxidation number
« Reply #5 on: February 14, 2018, 05:09:18 PM »
Comon error:

H2O  => O=-2  H =2

You are right about oxygen, but you have TWO hydrogen atoms, not one. Every hydrogen atom has its own oxidation number (as the atoms are equivalent, their oxidation numbers are identical).
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Offline peterschmidt3943

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Re: Oxidation number
« Reply #6 on: February 14, 2018, 05:15:14 PM »
so, H=1 and O=-2 ?

and what about the rest?

Offline Borek

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Re: Oxidation number
« Reply #7 on: February 15, 2018, 04:56:52 AM »
so, H=1 and O=-2 ?

Yes.

Quote
and what about the rest?

Try them again, knowing what you did wrong.
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