# caculate electrode potential of ethanol electrode

Watch
#1
the emf of ethanol oxygen fuel cell is 1.00v, calculate electrode potential for theethanol electrode. the oxygen half equation is given as o2+4H+ +4e- ---> 2h20 the electrode potential is +1.23. half equation for c2h5oh +3h2o----> 2co2 + 12h+ +12e-
emf of a cell= reduction + oxidation
the oxygen electrode is undergoing reduction , its more positive so the ethanol electrode must be oxidising, I thought u would have to do 1.00 (emf) - 1.23 (oxidation) = -0.23v but the actual answer is +0.23?

why is the answer positive, this was the method I was taught from school
0
2 years ago
#2
2CO2 + 12H+ +12e -> C2H5OH +3H2O E = ?
O2 +4H+ +4e- ---> 2H2O E = 1.23 V
Stop writing H20 for H2O. Water is 2 hydrogen atoms and 1 oxygen atom, not 20 hydrogen atoms.

Ecell = Ered - Eox
1 = 1.23 - ?
therefore ? = 0.23 V
0
#3
(Original post by BobbJo)
2CO2 + 12H+ +12e -> C2H5OH +3H2O E = ?
O2 +4H+ +4e- ---> 2H2O E = 1.23 V
Stop writing H20 for H2O. Water is 2 hydrogen atoms and 1 oxygen atom, not 20 hydrogen atoms.

Ecell = Ered - Eox
1 = 1.23 - ?
therefore ? = 0.23 V
sorry about that, why is the ethanol half equation flipped?
0
#4
sorry about that, why is the ethanol half equation flipped?
oh its because its getting reduced right?
2
2 years ago
#5
oh its because its getting reduced right?
When using Ered - Eox, this means 'the electrode potential of the electrode at which reduction is occuring' - 'the electrode potential of the electrode at which oxidation is occurring'. Electrode potentials are taken as electrode reduction potentials. Hence the way the half-equations are written is in the direction of a reduction process.
Last edited by username3249896; 2 years ago
0
#6
(Original post by BobbJo)
When using Ered - Eox, this means 'the electrode potential of the electrode at which reduction is occuring' - 'the electrode potential of the electrode at which oxidation is occurring'. Electrode potentials are taken as electrode reduction potentials. Hence the way the half-equations are written is in the direction of a reduction process.
so when using ered-eox, u write both equations as reduction?
0
2 years ago
#7
so when using ered-eox, u write both equations as reduction?
2CO2 + 12H+ +12e -> C2H5OH +3H2O E = ?
O2 +4H+ +4e- ---> 2H2O E = 1.23 V

Ecell = Ered - Eox
1 = 1.23 - ?
therefore ? = 0.23 V
0
X

new posts
Back
to top
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

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

### Poll

Join the discussion

#### What factors affect your mental health the most right now?

5.16%
Uncertainty around my education (296)
14.99%
Uncertainty around my future career prospects (209)
10.58%
Lack of purpose or motivation (276)
13.97%
Lack of support system (eg. teachers, counsellors, delays in care) (86)
4.35%
Impact of lockdown on physical health (112)
5.67%
Loneliness (174)
8.81%
Financial worries (71)
3.59%
Concern about myself or my loves ones getting/having been ill (87)
4.41%
Exposure to negative news/social media (92)
4.66%
Lack of real life entertainment (108)
5.47%
Lack of confidence in making big life decisions (175)
8.86%
Worry about missed opportunities during the pandemic (187)
9.47%