To recognize an alcohol, you need to identify specific functional groups within the molecule. The functional group characteristic of an alcohol is the hydroxyl group (-OH). This group is typically attached to a carbon atom in an organic molecule.
Let's examine each option provided:
A. It has an [tex]$-NH_2$[/tex] group attached to the molecule:
- The [tex]$-NH_2$[/tex] group is known as an amino group, which is characteristic of amines, not alcohols. Therefore, this option is not correct.
B. It has an -OH group attached to the end of the molecule:
- This is precisely the functional group that characterizes alcohols. The presence of an -OH group indicates that the molecule is an alcohol. Therefore, this option is correct.
C. It has a [tex]$C=O$[/tex] group attached to two R groups:
- The [tex]$C=O$[/tex] group, also known as a carbonyl group, is characteristic of ketones if it is attached to two alkyl or aryl groups (R groups). This is not indicative of an alcohol. So, this option is not correct.
D. It has an O molecule attached to two R groups:
- If an oxygen atom (O) is attached to two carbon-containing groups (R groups), it signifies an ether, not an alcohol. Therefore, this option is also incorrect.
Given these explanations, the correct answer to recognize an alcohol is:
B. It has an -OH group attached to the end of the molecule.
