NPT 4 P1 C 20

Ans given

(A) p q

(B) p q

by dilute do they mean very dilute??
If so then answer is true

why does it change in case of dil ???

I mean in (A) I got q r

(B) q r

ya for both its p,q

both Cl^- and ^-OH....GO TO ANODE BUT OH IS DISCAHRGED AS IT IS AT LOWER POSN IN ELEC CHEM SERIES.......HENCE O₂ IS GIVEN OUT AT ANODE

This might be helpful

http://jghs.edu.ky/Departments/Chemistry/chwselec.htm

Electrolysis of aqueous Sodium Chloride using Inert Electrodes

When very dilute solutions of sodium chloride are electrolysed, the results are also hydrogen (cathode) and oxygen (anode).

When moderately concentrated sodium chloride solution is electrolysed, the result is again hydrogen at the cathode, but this time chlorine gas is produced at the anode. Hydrochloric acid and other chlorides give similar results.

something to do with overvoltage i guess