Chemistry, Electrolysis of Aqueous Sodium Carbonate?

Question

Why would Humphrey Davy not get sodium when he electrolysed an aqueous solution of Sodium Carbonate?

Last question on Chem assessment and I WILL NOT LET IT BEAT ME!!!!

Sensible answers will get you 10 points!

Answer 1

Because the Sodium Carbonate is in solution in water - you would just get hydrogen and oxygen from the electrolysis.

Or to think of it another way, if you got Sodium, it would immediately react with the water in the solution to give hydrogen and dissolve into Sodium hydroxide.

If you want to make sodium from electrolysis you have to use moltern Sodium Carbonate (liquid but without the water) But it is not easy. Years ago I tried it with moltern Sodium Hydroxide (which melts at a much lower temperature) but I burnt out the diodes in my electric supply.
BTW it is dangerous - know what you are doing.

Answer 2

I don't have full standard reduction potential tables to hand, but in general for aqueous solutions the water will be either more readily reduced than one of the ions or more readily oxidised...
In this case, the reaction Na+ + e -> Na has E = -2.71 V and the reaction 2H2O + 2e -> H2 + 2OH- has E = -0.83

The more positive the SRP value the more easily reduced the species, so water is more easily reduced than Na...so instead of Na metal you'd get H2 gas and aqueous OH- as the reduction products. As others have said on here, the OH- would combine with the Na+ to give NaOH.
Hope that helps.

Answer 3

I've no idea why. Did he do it with Sodium Hydroxide?
Sorry. I've spent some time in Google but coulndn't find the WHY.
Could it be to do with the atomic bonding; like those in a carbonate are stronger than in a hydroxide?