Answer:
Isomers
Step-by-step explanation:
Compounds can have a same molecular formula (meaning, it contains the exact same amount of molecules) but a different structure, thus named differently. These are called isomers, and even a different structure of a compound can result in different physical properties such as boiling point and melting point.
1-propanol has a hydroxide group (OH) attached to the 1st end of the carbon chain. However, 2-propanol has a hydroxide group attached to the 2nd carbon chain, resulting in different IUPAC names and properties.