# Chemists: How Do I Calculate Half Wave Potential

AThousandYoung
Posers and Puzzles 01 Nov '04 09:45
1. AThousandYoung
All My Soldiers...
01 Nov '04 09:45
I am extremely frustrated. I am doing a lab report on electrochemistry and I cannot for the life of me figure out how to use E(1/2) to identify substances. How do I know what potential some reaction should appear at? For example, I know the &quot;standard potential&quot; of O2(g) + 4H+ + 4e- &lt;=&gt;2H2O = +1.229 V. This same textbook that gives me this information has a diagram where this reaction has an E(1/2) of ~-0.9 or -1 V vs SCE. Do I subtract 2.2 for the SCE to get the E^o=1.229? If so, how come this doesn't work for the peak they show at ~-0.1 for the reduction of O2 to H2O2? (-0.1 - 0.22 ~ -0.3 =/= - 0.68 = - E^o).
2. 04 Nov '04 16:01
Originally posted by AThousandYoung
I am extremely frustrated. I am doing a lab report on electrochemistry and I cannot for the life of me figure out how to use E(1/2) to identify substances. How do I know what potential some reaction should appear at? For example, I know the "standard potential" of O2(g) + 4H+ + 4e- <=>2H2O = +1.229 V. This same textbook that gives me this informa ...[text shortened]... eak they show at ~-0.1 for the reduction of O2 to H2O2? (-0.1 - 0.22 ~ -0.3 =/= - 0.68 = - E^o).
hey....simple....Calculate the full wave potential and divide it by 2....
3. AThousandYoung
All My Soldiers...
04 Nov '04 18:281 edit
STFU or I will smite thee. ðŸ˜‰

I found out. Apparently it's standard potential minus electrode potential. I was using the wrong reaction apparently.

THANKS FOR NOTHING RHP!!!1!
4. !~TONY~!
1...c5!
04 Nov '04 21:53
Originally posted by AThousandYoung
STFU or I will smite thee. ðŸ˜‰

I found out. Apparently it's standard potential minus electrode potential. I was using the wrong reaction apparently.

THANKS FOR NOTHING RHP!!!1!
I hate chemistry, and labs in general with a burning passion. Next Semester's Chem Lab is gonna be the death of me.