Test 2 Q6 part b ii


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Maya Gollamudi 1G
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Test 2 Q6 part b ii

Postby Maya Gollamudi 1G » Sun Mar 15, 2020 6:15 am

In part b of number 6 on Test 2:
A concentration cell was constructed with two electrodes containing CuSO4 at 25 degrees C. The cathode concentration is 2.2 M and cell potential is 0.0213 V. How will the following changes affect the cell potential?

ii) halving the mass of the anode electrode

Why does this have no effect?

madawy
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Joined: Fri Aug 09, 2019 12:17 am

Re: Test 2 Q6 part b ii

Postby madawy » Sun Mar 15, 2020 2:42 pm

Adding mass of reactants/products at the anode or cathode will not affect the cell potential, as Eº (and E) are intensive properties and do not depend on the quantity of oxidizing or reducing agents present.

Mulin_Li_2J
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Re: Test 2 Q6 part b ii

Postby Mulin_Li_2J » Sun Mar 15, 2020 4:00 pm

Standard cell potential is an intensive property because it is measured under standard conditions(1M solution, 1 atm, 298K, etc). I don't think cell potential is an intensive property because it's concentration-dependent according to the Nernst equation we derived in class. The way I understand this question is that when you halve the mass of an electrode, you don't really change the concentration of the electrolytes and that's way cell potential, as well, is not affected.

Rafsan Rana 1A
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Re: Test 2 Q6 part b ii

Postby Rafsan Rana 1A » Sun Mar 15, 2020 4:08 pm

In addition, if you look at the equation for it, mass isn't accounted for anywhere.

Shrayes Raman
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Re: Test 2 Q6 part b ii

Postby Shrayes Raman » Sun Mar 15, 2020 8:54 pm

Mass doesn't affect the overall reaction.

Kaitlyn Ang 1J
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Re: Test 2 Q6 part b ii

Postby Kaitlyn Ang 1J » Sun Mar 15, 2020 9:07 pm

Additionally, changing the mass of the electrode (the solid) doesn't affect anything. Only changing the concentration of aqueous ions will change E cell (because E cell = E standard - (RT/nF)lnQ


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