Cis and trans isomers are types of geometric isomers that occur in organic compounds with a carbon-carbon double bond alkenes . The terms "cis" and "trans" describe the relative positions of substituent groups around the double bond. In the case of but-2-ene C4H8 , there are two isomers: cis-but-2-ene and trans-but-2-ene.Structural Differences:1. Cis-but-2-ene: In this isomer, the two methyl groups CH3 are on the same side of the carbon-carbon double bond. This arrangement leads to a less symmetrical structure and causes the molecule to have a bent shape.2. Trans-but-2-ene: In this isomer, the two methyl groups are on opposite sides of the carbon-carbon double bond. This arrangement leads to a more symmetrical structure and causes the molecule to have a linear shape.Physical Properties:1. Boiling Point: Cis-but-2-ene has a higher boiling point than trans-but-2-ene. This is because the cis isomer has a less symmetrical structure, which leads to a larger surface area and stronger van der Waals forces between the molecules. As a result, more energy is required to separate the molecules in the cis isomer, leading to a higher boiling point.2. Melting Point: Cis-but-2-ene has a lower melting point than trans-but-2-ene. The less symmetrical structure of the cis isomer makes it more difficult to pack efficiently in a solid lattice, leading to weaker intermolecular forces and a lower melting point.3. Density: The densities of cis and trans isomers are generally similar, but slight differences may arise due to their different shapes and packing efficiencies in the liquid or solid state.Chemical Properties:The chemical properties of cis and trans isomers are generally quite similar, as they have the same molecular formula and functional groups. However, there may be some differences in reactivity due to the different spatial arrangements of the substituent groups around the double bond.1. Stability: Trans-but-2-ene is more stable than cis-but-2-ene. This is because the steric repulsion between the two methyl groups is minimized when they are on opposite sides of the double bond, as in the trans isomer. This lower steric strain makes the trans isomer more stable and less reactive.2. Reaction Stereoselectivity: The cis and trans isomers may exhibit different stereoselectivity in reactions involving the double bond, such as hydrogenation or addition reactions. The different spatial arrangements of the substituent groups can lead to different stereochemical outcomes in these reactions.In summary, cis and trans isomers of but-2-ene have different structural arrangements of their substituent groups around the carbon-carbon double bond, which leads to differences in their physical properties, such as boiling and melting points, and some differences in their chemical properties, such as stability and reaction stereoselectivity.