How would you distinguish between the following pairs of...

How would you distinguish between the following pairs of compounds using simple chemical tests? Tell what you would do and what you would see.
(a) Cyclopentene and cyclopentane
(b) 2 -Hexene and benzene

Key Concepts

Electrophilic Addition Reactions

Electrophilic addition reactions are characteristic of compounds with carbon–carbon double bonds. In these reactions, an electrophile, such as bromine, adds to the electron-rich double bond, leading to the formation of a vicinal dihalide. This reaction is a useful test for the presence of unsaturation in a molecule because alkenes, unlike alkanes or aromatic compounds, readily undergo this type of reaction.

Aromaticity and Resonance Stabilization

Aromaticity refers to the special stability exhibited by cyclic compounds with conjugated ?-electron systems, like benzene. This stability, due to resonance, makes aromatic compounds less reactive toward addition reactions that would disrupt the conjugated system. Consequently, aromatic compounds do not react with electrophiles under mild conditions that readily react with isolated double bonds in alkenes.

Bromine Test

The bromine test is a simple chemical test based on the electrophilic addition reaction of halogens to unsaturated compounds. When a bromine solution is added to a compound containing a carbon–carbon double bond (an alkene), the bromine is consumed, causing the solution to lose its color. In contrast, saturated compounds such as alkanes, or aromatic compounds that resist addition without a catalyst, do not change the color of the bromine solution.

Transcript

Please give Ace some feedback