Galvanic Cell (1 Viewer)

[hothand621]

Why when you decrease the concentration of electrolytes in both half cells of a galvanic cell does the voltage increase? Both electrolytes were NaCl????

 

[strawberrye]

Are you sure you haven't made an error when you did the experiment? Because in theory, increase in concentration of electrolyte should increase voltage, and likewise, a decrease in concentration-i.e. via dilution with water should decrease the voltage(EMF) obtained.

 

[hothand621]

Are you sure you haven't made an error when you did the experiment? Because in theory, increase in concentration of electrolyte should increase voltage, and likewise, a decrease in concentration-i.e. via dilution with water should decrease the voltage(EMF) obtained.

Well it was a class examination and when over 20 groups did it, we all got the same result. The voltage went up everytime!

Also I have another question, can graphite be used as a cathode in a galvanic cell?

 

[someth1ng]

You need to have a look at the Nernst equation for this.

This is first year chemistry at tertiary level so you won't know it. You need to know the half reactions of the cell and the overall reaction to find Q and z.

I can't really help further without more details.

It's possible to get really high voltages with galvanic cells by making one half cell have a very low concentration and one with very high concentration such that entropy (the effect that shows that things get more disordered) will increase.

 

[strawberrye]

Well it was a class examination and when over 20 groups did it, we all got the same result. The voltage went up everytime!

Also I have another question, can graphite be used as a cathode in a galvanic cell?

Yes, graphite can be used as a cathode in a galvanic cell

 

[anomalousdecay]

You need to have a look at the Nernst equation for this.

This is first year chemistry at tertiary level so you won't know it. You need to know the half reactions of the cell and the overall reaction to find Q and z.

I can't really help further without more details.

It's possible to get really high voltages with galvanic cells by making one half cell have a very low concentration and one with very high concentration such that entropy (the effect that shows that things get more disordered) will increase.

This is very interemistation.
Can we start an extracurricular thread here like for maths?

 

[someth1ng]

This is very interemistation.
Can we start an extracurricular thread here like for maths?

I'm happy for you to start one if you want.