In our electro-chemistry lessons we were told that if we electrolyze dilute NaOH,the concentrations of Na+
will not changes..yes it's true as the cathode introduce OH-
to the solution as anode removes OH-
from solution ..so the concentrations don't vary..
But in our industrial chemistry lessons,it says something different..Well its about Chloralkali process(diaphragm cell process) which prepares NaOH from NaCl(aq)
This is quoted from my book.
(7)Electrolysis is stopped when the concentration of NaOH is at a higher point.
If it was hydrolyzed too long O2 will bubble off instead of Cl2.
(Then the concentration of OH-will drop down and reduces amount NaOH product)
(8.)Then the aqueous solution of NaCl and NaOH is electrolyzed again.
concentration is low at first, OH-
will not be discharged till Cl-
concentration gets low..I understand it..
Ok now let's take that Cl-
concentration is low right now..then OH-
will start to discharge but according to elecro-chemistry lessons the concentration of OH-
will not get vary...
Ok lets imagine that it reduces the amount of OH-
...then what happens to Na+
in the solution..It must go with some anion..How..who will give anoins to Na+
..low concentration of Cl-
is with a same concentration of Na+
...So what will happen to newer Na+
Also the 7th and 8th points in my book equated about..seems so bizarre to me...First it says no,then it says yes..
Please someone help me understand....!