Physical and Chemical Properties — Predicted 2026

AI-Predicted Question Angles for UPSC 2026

Based on trend analysis, current affairs, and recurring themes in Physical and Chemical Properties.

Stereoselective Synthesis of Alkenes

high

NEET frequently tests the ability to control stereochemistry in organic synthesis. Questions involving the conversion of an alkyne to a specific cis- or trans-alkene using Lindlar's catalyst or Na/liq. NH3 are highly probable. Students should be prepared to identify the correct reagent for a desired stereoisomer and understand the underlying syn/anti-addition principles. A common question type could be a reaction scheme where an alkyne is converted to a cis-alkene, and then further reacted, requiring knowledge of both steps.

Identification of Unknown Alkynes via Reaction Products

medium

Problems that provide the molecular formula of an alkyne and then describe its reaction products (e.g., ozonolysis products, hydration products) are excellent for testing comprehensive understanding. For example, an alkyne $C_5H_8$ gives a specific ketone on hydration, or specific carboxylic acids on oxidative cleavage. This requires working backward from the products to deduce the structure of the original alkyne, integrating knowledge of Markovnikov's rule and oxidative cleavage patterns.

Comparative Acidity and Basicity in Reaction Context

high

The acidity of terminal alkynes is a distinctive property. Questions comparing the acidity of terminal alkynes with water, alcohols, or other hydrocarbons, or asking which bases can deprotonate an alkyne, are very common. Students might be asked to identify a reaction that will NOT occur due to insufficient basicity of the reagent (e.g., terminal alkyne with NaOH). Understanding the relative strengths of acids and bases is crucial here.