Isomerism in Coordination Compounds — Predicted 2026

AI-Predicted Question Angles for UPSC 2026

Based on trend analysis, current affairs, and recurring themes in Isomerism in Coordination Compounds.

Identification of Isomer Pairs with Mixed Types

high

NEET often tests the ability to distinguish between closely related isomer types. A question might present four pairs of complexes, each exhibiting a different type of isomerism (e.g., one pair is ionization, another is linkage, another is geometrical, and one is not isomeric), asking to identify the pair showing a specific type. This requires precise knowledge of all definitions and common examples. Students must be able to quickly analyze the differences in connectivity and spatial arrangement for each pair.

Counting Total Stereoisomers (Geometrical + Optical) for Complex Cases

medium

While simple counting for $MA_2B_2$ or $M(AA)_3$ is common, a slightly harder question could ask for the total number of stereoisomers (including both geometrical and optical) for a complex like $M(AA)_2B_2$ or $M(AA)B_2C_2$. For $M(AA)_2B_2$, the cis-isomer is optically active (2 enantiomers), while the trans-isomer is achiral (1 isomer), leading to a total of 3 stereoisomers. This requires a combined understanding of both geometrical and optical isomerism and the ability to check for chirality in each geometrical isomer.

Application of Isomerism in Biological/Industrial Contexts

low

While less common for direct questions, NEET sometimes includes application-based questions. For isomerism, this could involve the biological activity of cisplatin (cis-isomer is anti-cancer, trans-isomer is inactive) or the role of isomerism in enzyme specificity. Such questions test not just the identification of isomers but also the understanding of why different isomers have different properties, linking chemistry to biology or real-world uses. This would likely be a conceptual question rather than a calculation.