How many structural isomers possessing the alcohol functional group have the molecular formula C₃H₈O? A) 1 B) 2 C) 3 D) 4 E) 5

Question

Quizplus · Accepted Answer

To determine the number of structural isomers with the alcohol functional group and the given molecular formula, we need to identify all possible ways of arranging the atoms. By counting the number of carbon atoms, we can see that there are 13 carbons. Since the molecular formula contains only one sulfur and one oxygen atom, we can place them in the molecule to obtain three different possibilities: 
1) sulfur and oxygen attached to the same carbon atom 
2) sulfur and oxygen attached to different carbon atoms 
3) sulfur and oxygen each bonded to a separate carbon atom which is also bonded to a hydrogen atom 
Next, we need to distribute the remaining hydrogen atoms to satisfy the valency requirements of each atom. Since the molecular formula contains 18 hydrogen atoms, and each carbon atom must have four bonds, we can place (18-1-1) = 16 hydrogen atoms in the molecule. We can place two hydrogens on each carbon atom that is not bonded to sulfur or oxygen, and one hydrogen on the carbon atom that is bonded to sulfur or oxygen. 
By following this process, we can find four different structural isomers with the alcohol functional group: 
1) CH3-CH2-CH2-CH2-CH2-CH2-CH2-CH2-OH 
2) CH3-CH2-CH2-S-CH2-CH2-CH2-CH2-OH 
3) CH3-CH2-CH2-S-CH2-CH2-CH2-CH(OH)-CH3 
4) CH3-CH2-CH2-S-CH2-CH2-CH2-CH(OH)-CH2-CH3

How Many Structural Isomers Possessing the Alcohol Functional Group Have