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cianfa72
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- About the equilibrium reached at Daniell cell electrodes without any external connection
Hello,
consider again a simple Daniell cell with salt bridge in place but no external electric connection between electrodes.
Reading from some source e.g. link1 it seems upon Zinc and Copper metal rods are dipped into their own ions solution, both will gain a negative charge (-) due to an excess of electrons gained inside themselves (metal atoms get oxidised). Having Zinc and Copper different electronegativity, the amount of electrons gained on each electrode will be not the same resulting in a potential difference voltage between them.
From other sources instead (e.g. link2), the Copper rod (Cathode) will behave the other way around: Cu++ ions reduction will take place "stealing" electrons from the Copper rod leaving it positively charged (in other words there will be a depletion of electrons inside the Copper metal rod with an unbalance between protons and electrons inside it)
Which is the truth ?
consider again a simple Daniell cell with salt bridge in place but no external electric connection between electrodes.
Reading from some source e.g. link1 it seems upon Zinc and Copper metal rods are dipped into their own ions solution, both will gain a negative charge (-) due to an excess of electrons gained inside themselves (metal atoms get oxidised). Having Zinc and Copper different electronegativity, the amount of electrons gained on each electrode will be not the same resulting in a potential difference voltage between them.
From other sources instead (e.g. link2), the Copper rod (Cathode) will behave the other way around: Cu++ ions reduction will take place "stealing" electrons from the Copper rod leaving it positively charged (in other words there will be a depletion of electrons inside the Copper metal rod with an unbalance between protons and electrons inside it)
Which is the truth ?
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