How many different isomers are there for a compound having the molecular formula CzH6O? A) 4 B) 5 C) 6 D) 7
The correct answer and explanation is:
The molecular formula C2H6O represents a compound that can have different structural isomers, depending on the arrangement of atoms and functional groups. There are 4 different isomers for C2H6O. The correct answer is A) 4.
Here’s a breakdown of the possible isomers:
- Ethanol (CH3CH2OH): Ethanol is a simple alcohol where the functional group -OH is attached to an ethyl group (C2H5). It is a straight-chain alcohol with the simplest structure.
- Dimethyl Ether (CH3OCH3): In this ether, the two methyl groups (CH3) are bonded to an oxygen atom. This is another form of C2H6O, where the functional group is an ether (-O-) rather than an alcohol.
- Ethenol (CH2=CH-OH): Ethenol is an enol (an alcohol where a double bond is present in the structure). It consists of an ethene (C2H4) backbone, with a hydroxyl (-OH) group attached to one of the carbon atoms involved in the double bond. However, this structure is highly unstable in its pure form and usually undergoes tautomerization to form ethanol.
- Ethylene glycol (HOCH2CH2OH): This compound is also an alcohol but differs from ethanol by having two hydroxyl (-OH) groups attached to each carbon atom, making it a diol.
These four isomers can exist under different conditions and are considered structural isomers because they differ in the connectivity of atoms, despite having the same molecular formula. The key to understanding these isomers lies in recognizing the different ways that oxygen can be incorporated into the structure, either as part of an alcohol group or an ether.