October 31, 2024, 08:16:46 PM
Forum Rules: Read This Before Posting


Topic: Electrolysis NaCl  (Read 14137 times)

0 Members and 2 Guests are viewing this topic.

Offline LeFowl

  • Regular Member
  • ***
  • Posts: 16
  • Mole Snacks: +0/-0
Electrolysis NaCl
« on: June 18, 2009, 01:14:44 AM »
At the end of an electrolysis with an electrolyte of concentrated NaCl sol'n and inert elctrodes, will the electrolyte be acidic,neutral or basic????

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27820
  • Mole Snacks: +1808/-412
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: Electrolysis NaCl
« Reply #1 on: June 18, 2009, 02:57:37 AM »
Write reaction equations.
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline LeFowl

  • Regular Member
  • ***
  • Posts: 16
  • Mole Snacks: +0/-0
Re: Electrolysis NaCl
« Reply #2 on: June 18, 2009, 11:16:05 AM »
2Cl-(aq) -2e-  :rarrow: Cl2(g)
2H+(aq) +2e-  :rarrow: H2(g)

Offline killer120

  • New Member
  • **
  • Posts: 7
  • Mole Snacks: +0/-0
Re: Electrolysis NaCl
« Reply #3 on: June 18, 2009, 11:48:22 AM »
2Cl-(aq) -2e-  right arrow Cl2(g)
2H+(aq) +2e-  right arrow H2(g)
i think if the electrolysis experiment really continue until the end...the electrolyte will become basic because there will be a lot OH- ions inside it.....am i right? ???

Offline LeFowl

  • Regular Member
  • ***
  • Posts: 16
  • Mole Snacks: +0/-0
Re: Electrolysis NaCl
« Reply #4 on: June 18, 2009, 11:49:44 AM »
well i had a test yesterday and that was one of the questions XD. i put basic. we didn't even do this sstuff in class

Offline LeFowl

  • Regular Member
  • ***
  • Posts: 16
  • Mole Snacks: +0/-0
Re: Electrolysis NaCl
« Reply #5 on: June 18, 2009, 01:42:48 PM »
so can anyone tell me whether it will be acidic, neutral or basic?

Offline Stephen

  • Regular Member
  • ***
  • Posts: 48
  • Mole Snacks: +1/-1
Re: Electrolysis NaCl
« Reply #6 on: June 18, 2009, 03:29:37 PM »
At the end of an electrolysis with an electrolyte of concentrated NaCl sol'n and inert elctrodes, will the electrolyte be acidic,neutral or basic????
Well, if I understand question well(not from USA or etc)....I'd say neutral...
You know that NaOH is strong base and HCl is strong acid ==>there is no electrolysis and there is going to be neutral solution....But this is just if i understood question good:D

Greetings

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27820
  • Mole Snacks: +1808/-412
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: Electrolysis NaCl
« Reply #7 on: June 18, 2009, 03:32:14 PM »
killer is right.

Think: where does H+ come from? What must be left in the solution?
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline LeFowl

  • Regular Member
  • ***
  • Posts: 16
  • Mole Snacks: +0/-0
Re: Electrolysis NaCl
« Reply #8 on: June 18, 2009, 07:31:07 PM »
Thanks alot =D

Offline dufengtao

  • Regular Member
  • ***
  • Posts: 22
  • Mole Snacks: +0/-0
  • Gender: Male
Re: Electrolysis NaCl
« Reply #9 on: June 18, 2009, 10:52:23 PM »
NaCl+H2O :rarrow:Cl2+H2+NaOH. This equation has the answer in it's production.

Offline 408

  • Chemist
  • Full Member
  • *
  • Posts: 796
  • Mole Snacks: +103/-30
Re: Electrolysis NaCl
« Reply #10 on: June 19, 2009, 01:13:20 AM »
Note that while you may think H2O is the strongest reducing agent present which would end up giving H+ to cancel the OH-, H2O needs an overpotential, so Cl- oxidation is preferred, giving Cl2.

Some Cl2 will react with the NaOH giving hypo chlorite and chlorate, but the amount that escapes means the cell goes basic.

Overpotential see here: http://en.wikipedia.org/wiki/Overpotential

Offline killer120

  • New Member
  • **
  • Posts: 7
  • Mole Snacks: +0/-0
Re: Electrolysis NaCl
« Reply #11 on: June 19, 2009, 02:35:17 AM »
but i got one question to ask you all....actually where does the water (H+ and OH-) come from?i thought the NaOH solution is concentrated....so why still has water exist in the solution?can you all help me?explain to me... ???

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27820
  • Mole Snacks: +1808/-412
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: Electrolysis NaCl
« Reply #12 on: June 19, 2009, 02:45:13 AM »
actually where does the water (H+ and OH-) come from?i thought the NaOH solution is concentrated....so why still has water exist in the solution?

As long as it is solution it contains water (or some other solvent) by definition.

I am not sure what your problem is.
« Last Edit: June 28, 2009, 03:28:29 AM by Borek »
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline pip

  • Very New Member
  • *
  • Posts: 2
  • Mole Snacks: +0/-0
Re: Electrolysis NaCl
« Reply #13 on: June 27, 2009, 11:16:02 PM »
Electrolysis of saturated sodium chloride is THE lab synthesis of sodium chlorate all this Cl2 and H+ talk seems unlikely as H2 is formed not H+

NaCl + 3H2O → NaClO3 + 3H2

Sponsored Links