Electrolysis — Predicted 2026

AI-Predicted Question Angles for UPSC 2026

Based on trend analysis, current affairs, and recurring themes in Electrolysis.

Quantitative problems involving gas volumes at STP

high

NEET often combines electrochemistry with mole concept and gas laws. Expect questions asking for the volume of $H_2$ or $O_2$ liberated at STP, given current and time, or vice-versa. This requires calculating moles of gas using Faraday's laws and then converting to volume using $22.4, ext{L/mol}$ at STP. Students need to be careful with the stoichiometry of gas evolution reactions (e.g., $2H_2O \rightarrow O_2 + 4H^+ + 4e^-$ means 4 moles of electrons for 1 mole of $O_2$).

Product prediction with active electrodes

medium

While inert electrodes are common, questions involving active electrodes (e.g., copper anode in $CuSO_4$ solution) are a good test of conceptual understanding. Students must recognize that the active anode itself can oxidize if its oxidation potential is lower than that of other anions or water. This adds another layer of complexity to product prediction, moving beyond simple potential comparisons.

Impact of pH on electrolysis products

medium

The reduction potential of $H_2O$ and $H^+$ ($2H_2O + 2e^- \rightarrow H_2 + 2OH^-$ and $2H^+ + 2e^- \rightarrow H_2$) and the oxidation potential of $H_2O$ ($2H_2O \rightarrow O_2 + 4H^+ + 4e^-$) are pH-dependent. Questions might explore how changing the pH of an aqueous solution affects the products, especially in cases where $H^+$ or $OH^-$ are involved in the competing electrode reactions. This tests a deeper understanding of Nernst equation principles in a qualitative manner.