C2H6O alcohol has how many Lewis structures? What is the name of the alcohol?
The correct answer and explanation is:
Correct Answer:
C₂H₆O has one Lewis structure as an alcohol, and the name of this alcohol is ethanol.
Explanation:
The molecular formula C₂H₆O represents two possible structural isomers: ethanol and dimethyl ether. These have the same number and types of atoms but different arrangements. However, only one of them is classified as an alcohol, and that is ethanol.
In organic chemistry, an alcohol is defined as a compound containing a hydroxyl group (–OH) bonded to a saturated carbon atom. Ethanol fits this definition because it consists of a two-carbon chain where one carbon is bonded to an –OH group. Its molecular structure can be written as CH₃CH₂OH.
The Lewis structure for ethanol shows:
- The central framework consists of two carbon atoms (C–C single bond).
- The first carbon (CH₃) is bonded to three hydrogen atoms.
- The second carbon (CH₂) is bonded to two hydrogen atoms and one hydroxyl group (–OH).
- The oxygen atom in the hydroxyl group has two lone pairs of electrons and forms single bonds with the second carbon and a hydrogen atom.
Thus, there is only one Lewis structure for the alcohol form of C₂H₆O, which is ethanol. The other isomer, dimethyl ether (CH₃OCH₃), is not an alcohol and has a different functional group called an ether. Ethers have an oxygen atom bonded to two carbon atoms instead of being bonded to hydrogen, which distinguishes them from alcohols.
Ethanol is a well-known compound, commonly used as a solvent, a fuel additive, and the active ingredient in alcoholic beverages. Its structure and classification as an alcohol are important in understanding its chemical behavior and physical properties. Therefore, when asked about the alcohol form of C₂H₆O, there is only one valid Lewis structure and it represents ethanol.