# Electrolysis question

1. Nov 6, 2009

### plexus0208

1. The problem statement, all variables and given/known data
Why does electrolysis of molten NaCl yield sodium and chlorine, while electrolysis of a solution of NaCl in water yields sodium hydroxide and chlorine.

2. Relevant equations

3. The attempt at a solution
Is it because H+ is more readily reduced than Na+?

2H+ + 2e --> H2 Eo= 0
2Cl- --> Cl2 + 2e Eo=-1.358

Thus, 2H+ + 2Cl- --> Cl2 H2 Eorxn=-1.358 V

And so 2H+ --> H2, leaving OH- behind in place of Cl-

Last edited: Nov 7, 2009
2. Nov 7, 2009

### Staff: Mentor

Any ideas? You see, that template that you should use is not a joke, but a tool to force you follow forum rules.

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methods

3. Nov 7, 2009

### plexus0208

Is it because H+ is more readily reduced than Na+?

2H+ + 2e --> H2 Eo= 0
2Cl- --> Cl2 + 2e Eo=-1.358

Thus, 2H+ + 2Cl- --> Cl2 H2 Eorxn=-1.358 V

And so 2H+ --> H2, leaving OH- behind in place of Cl-

Last edited: Nov 7, 2009
4. Nov 7, 2009

### Staff: Mentor

Yes. Note that further discussion is irrelevant, as you should compare reduction potentials of H+ and Na+, chlorine reaction doesn't change.

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methods