JAMB - Chemistry (2001 - No. 39)
The pair of organic compounds that are isomers is
Benzene and methylbenzene
Trichloromethane and tetrachloromethane
Ethanol and propane
But-1-ene and but-2-ene
Paliwanag
Isomers refer to compounds that have the same molecular formula but are structurally different. Both But-1-ene and But-2-ene have the same number of Carbons and the same number of Hydrogen. The only difference is the positions of the double bond. Therefore, they are isomers