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Karnataka Board PUCPUC Science 2nd PUC Class 12

How will the pH of brine (aq. NaCl solution) be affected when it is electrolysed? - Chemistry

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Question

How will the pH of brine (aq. \[\ce{NaCl}\] solution) be affected when it is electrolysed?

Short/Brief Note
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Solution

\[\ce{NaCl (aq) -> Na^{+} (aq) + Cl^{-} (aq)}\]

Cathode: \[\ce{H2O(l) + e^{-} -> 1/2 H2(g) + OH^{-} (aq)}\]

Anode: \[\ce{Cl^{-} (aq) -> 1/2 Cl2(g) + e^{-}}\]

Overall reaction: \[\ce{NaCl(aq) + H2O(l) -> NaOH(aq) + H2(g) + Cl2(g)}\] 

\[\ce{NaOH}\] is a strong base, they turn the brine solution basic and pH will increase.

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Chapter 3: Electrochemistry - Exercises [Page 39]

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NCERT Exemplar Chemistry [English] Class 12
Chapter 3 Electrochemistry
Exercises | Q III. 39. | Page 39

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