100 Q&A on Isomerism in Organic Chemistry (JEE/NEET Focus) Part 1: Basic Concepts and Structural Isomerism Q. No. Question Answer 1 Define Isomers. Compounds having the same molecular formula but different physical or chemical properties. 2 What is Structural Isomerism? Isomers having the same molecular formula but different connectivity (sequence of bonding). 3 What are the five main types of structural isomerism? Chain, Position, Functional, Metamerism, and Tautomerism. 4 Define Chain Isomerism. Isomers differing in the arrangement of the carbon skeleton (straight chain vs. branched chain). 5 Give one example of chain isomers (C5​H12​). n-Pentane and Isopentane (2-Methylbutane). 6 Define Position Isomerism. Isomers differing in the position of the functional group or substituent on the same carbon chain. 7 Give one example of position isomers (C3​H7​Cl). 1-Chloropropane and 2-Chloropropane. 8 Define Functional Isomerism. Isomers having the same molecular formula but differe...