why? (1 Viewer)

[Fade1233]

In electrolysis of dilute HCl, Why are sodium ions not oxidised instead of H2O? and why is h20 reduced instead of chlorine in both concentrated and dilute.

 

[dan964]

In electrolysis of dilute HCl, Why are sodium ions not oxidised instead of H2O? and why is h20 reduced instead of chlorine in both concentrated and dilute.

firstly can I point out that it is supposed to be NaCl electrolysis.
Its probably related to the concentration of the Na ions present.
more importantly it is due to the electrical conductivity
dilute NaCl - poor conductivity - so water is reduced to hydrogen gas and water is also reduced to oxidation preferentially to Na and Cl
concentrated NaCl - better conductivity - so water is reduced to hydrogen gas, and chlorine is oxidised to chlorine gas. (Sodium is very non-electronegative)
molten NaCl - even better conductivity - so sodium is reduced, chlorine is oxidised.

 

[Fade1233]

firstly can I point out that it is supposed to be NaCl electrolysis.
Its probably related to the concentration of the Na ions present.
more importantly it is due to the electrical conductivity
dilute NaCl - poor conductivity - so water is reduced to hydrogen gas and water is also reduced to oxidation preferentially to Na and Cl
concentrated NaCl - better conductivity - so water is reduced to hydrogen gas, and chlorine is oxidised to chlorine gas. (Sodium is very non-electronegative)
molten NaCl - even better conductivity - so sodium is reduced, chlorine is oxidised.

Ye my bad NaCl. I understand dilute that not much conc hence water; but in concentrated, what about in terms of redox?

 

[Queenroot]

What are the values of their reduction potentials?