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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: dancing1101 on December 01, 2007, 10:39:19 PM

Title: Yr 12 Chem help oxidation reduction
Post by: dancing1101 on December 01, 2007, 10:39:19 PM
hey
to work out oxidation reduction things i know that oxidation is loss and reduction is gain but ok i have a question where we have to figure out if it is oxidation or reduction from the half equation and it doesn't have any charges so i dont know whether its loss or gain probably a stupid question;

NH3 ==> N2
i thought the N might be gaining but then i thought that the H was losing  ???
any help would be great]
thanks!
Title: Re: Yr 12 Chem help oxidation reduction
Post by: TJGuitarZ on December 01, 2007, 11:02:12 PM
I just covered this in my organic chemistry class -- though I haven't reviewed the material enough to be comfortable. I'll try to help the best I can.

An oxidation is when a molecule LOSES electrons. A reduction is when a molecule GAINS electrons. NH3 has more electrons (5 from N and 3 from H), whereas the N2 has less electrons (5 from N, and 2 from H). Therefore, decreasing in electrons means you are undergoing an oxidation.

This is what makes most sense to me, but I'd wait for one of the chemistry buffs to clear things up.
Title: Re: Yr 12 Chem help oxidation reduction
Post by: agrobert on December 01, 2007, 11:19:43 PM

OIL RIG

Oxidation Is Loss Reduction Is Gain

Never forget.

Title: Re: Yr 12 Chem help oxidation reduction
Post by: Borek on December 02, 2007, 04:46:29 AM
i thought the N might be gaining but then i thought that the H was losing

You are most likely asked to compare so called oxidation numbers (http://www.chembuddy.com/?left=balancing-stoichiometry&right=oxidation-numbers-method).
Title: Re: Yr 12 Chem help oxidation reduction
Post by: Borek on December 02, 2007, 04:52:48 AM
whereas the N2 has less electrons (5 from N, and 2 from H).

N2 doesn't have 2 electrons from H, moreover, it doesn't have 5 electrons per N - unless you are quietly ignoring non-valence 1s2 electrons.