A. Types of Hydrocarbons Models of Unsaturated Hydrocarbons Name Ethene Propene Cyclobutene cis-2-Butene Ethyne (acetylene) Condensed Structural Formula
The Correct Answer and Explanation is:
Corrected Table: Types of Hydrocarbons – Unsaturated Hydrocarbons
| Name | Condensed Structural Formula |
|---|---|
| Ethene | CH₂=CH₂ |
| Propene | CH₂=CH–CH₃ |
| Cyclobutene | C₄H₆ (ring structure with one double bond) |
| cis-2-Butene | CH₃–CH=CH–CH₃ (cis configuration) |
| Ethyne (acetylene) | HC≡CH |
Explanation
Unsaturated hydrocarbons are organic compounds that contain at least one double or triple bond between carbon atoms. These bonds reduce the number of hydrogen atoms in the molecule compared to saturated hydrocarbons, which only contain single bonds.
1. Ethene (CH₂=CH₂):
Ethene, also known as ethylene, is the simplest alkene. It contains a carbon-carbon double bond, making it an unsaturated hydrocarbon. Each carbon in the double bond is bonded to two hydrogen atoms. Ethene is a key raw material in the production of plastics like polyethylene.
2. Propene (CH₂=CH–CH₃):
Propene, or propylene, has three carbon atoms with a double bond between the first and second carbon. The third carbon is bonded to the second, forming a methyl group (–CH₃). Propene is used in making polypropylene and various industrial chemicals.
3. Cyclobutene (C₄H₆):
Cyclobutene is a cyclic alkene with four carbon atoms forming a ring and one carbon-carbon double bond. It’s unsaturated due to the presence of this double bond. The ring structure adds strain, making cyclic alkenes less stable than their linear counterparts.
4. cis-2-Butene (CH₃–CH=CH–CH₃):
In cis-2-butene, the two methyl groups (CH₃) are on the same side of the double bond between the second and third carbon atoms. This “cis” configuration affects the compound’s physical properties, like boiling point and polarity, compared to the “trans” isomer.
5. Ethyne (HC≡CH):
Also known as acetylene, ethyne is the simplest alkyne. It features a triple bond between two carbon atoms. This makes it more reactive than alkenes. Ethyne is widely used in welding torches due to its high flame temperature when burned with oxygen.
These models demonstrate the diversity of unsaturated hydrocarbons in structure and reactivity.
