Comprehension:
Electrolysis
In the electrolysis process, the nature of material being electrolyzed, and the electrodes nature are the important factors in predicting the products of electrolysis. The electrode material, whether acting as a source or sink or itself, is not inert will also decides the nature of the product of the electrolysis. The standard electrode potentials of the various oxidizing and reducing species present in the electrolytic mixture also decides the product of electrolysis. The voltage applied also decides the product of electrolysis since some of the reactions which are feasible are so slow kinetically that they are not seem to take place at lower voltage. The quantitative aspects of electrolysis was described by Faraday law of electrolysis.
Which of the following does not affect the products formed during electrolysis?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Nature of inert electrode
The products of electrolysis depend on several factors, one of which is the type of electrode.
An inert electrode (platinum or gold) does not take part in the reaction; it only acts as a source or sink for electrons. So it makes no difference which inert electrode is used. A reactive electrode, however, can take part and change the products:
CuSO4(aq) with Pt anode: \( \ce{2H2O -> O2 + 4H^+ + 4e^-} \)
CuSO4(aq) with Cu anode: \( \ce{Cu -> Cu^2+ + 2e^-} \)
Option (1) Nature of material being electrolysed — Affects the products. For example, molten NaCl gives sodium at the cathode, but aqueous NaCl gives hydrogen.
Option (2) Applied voltage — Affects the products. Because of overpotential, a reaction that is favoured by E° may not take place at a low voltage, so a different product forms.
Option (3) Nature of inert electrode — Does not affect the products. An inert electrode (platinum or gold) takes no part in the reaction; it only acts as a source or sink for electrons, so it makes no difference which inert electrode is used.
Option (4) Standard electrode potential — Affects the products. Of the species that can react, the one with the higher reduction potential is reduced first at the cathode.
NCERT (2026-27 edition):
Products of Electrolysis
