Concentration and cell potential


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504939134
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Joined: Wed Sep 18, 2019 12:21 am

Concentration and cell potential

Postby 504939134 » Sun Feb 23, 2020 3:25 pm

Can someone please explain how concentration affects cell potential? And how Le Chatelliers principle plays a role in this?

Riya Sood 4G
Posts: 160
Joined: Sat Aug 24, 2019 12:18 am

Re: Concentration and cell potential

Postby Riya Sood 4G » Sun Feb 23, 2020 3:44 pm

Le Chateliers principle can be used to make some predictions.
1. When (reactant) > 1, we assume Ecell > Ecell (standard conditions)
2. When (product)>1, we assume E cell < Ecell (standard conditions)

Le-Chateliers principle is not useful because we cannot calculate cell potential from that method. As such, we use the Nernst equation which helps us calculate the cell potential for any concentrations under non-standard conditions.

Jiyoon_Hwang_2I
Posts: 101
Joined: Sat Sep 14, 2019 12:17 am

Re: Concentration and cell potential

Postby Jiyoon_Hwang_2I » Sun Feb 23, 2020 3:45 pm

Changing the concentration of a solution will increase the concentration gradient between the two solutions, causing the voltage potential to increase. Since the two solutions are further away from equilibrium, Le Chatelier's principle will be implemented to bring the two solutions back to equilibrium.

Adriana_4F
Posts: 74
Joined: Fri Sep 28, 2018 12:29 am

Re: Concentration and cell potential

Postby Adriana_4F » Sun Feb 23, 2020 3:54 pm

Think of how an increase in the concentration of reactants will increase the formation of products
The same will happen for Ecell. Ecell will increase

Robert Tran 1B
Posts: 118
Joined: Thu Jul 11, 2019 12:15 am

Re: Concentration and cell potential

Postby Robert Tran 1B » Sun Feb 23, 2020 5:37 pm

Another way to see cell potential is the potential of the cell to do work. If there is a greater difference between the concentrations of the reactants in a spontaneous reaction, it will be able to do more work.

DHavo_1E
Posts: 118
Joined: Sat Aug 17, 2019 12:17 am

Re: Concentration and cell potential

Postby DHavo_1E » Sun Feb 23, 2020 7:32 pm

Riya Sood 4G wrote:Le Chateliers principle can be used to make some predictions.
1. When (reactant) > 1, we assume Ecell > Ecell (standard conditions)
2. When (product)>1, we assume E cell < Ecell (standard conditions)

Le-Chateliers principle is not useful because we cannot calculate cell potential from that method. As such, we use the Nernst equation which helps us calculate the cell potential for any concentrations under non-standard conditions.


Hello,

Can you explain how you got the observations above? Also, are standard conditions 1M and 25 degrees Celsius? Thank you!

Emily Chirila 2E
Posts: 112
Joined: Sat Jul 20, 2019 12:16 am

Re: Concentration and cell potential

Postby Emily Chirila 2E » Sun Feb 23, 2020 7:37 pm

These observations come from Le Chatelier's Principle.

Increasing concentration of reactants leads to formation of products, thus Ecell will be larger than Ecell at standard conditions
Increasing concentration of products leads to formation of reactants, thus Ecell will be smaller than Ecell at standard conditions


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