In Chemistry, how many isomers does Butanol (C4H9OH) have?

Butanol (C4H9OH) has four isomers due to the different arrangements of its carbon and hydrogen atoms. The four isomers are classified as primary (1-butanol), secondary (2-butanol), tertiary (2-methyl-2-propanol), and a positional isomer (1-methyl-1-propanol). In 1-butanol, the hydroxyl group is attached to the first carbon atom (C1) of the carbon chain. In 2-butanol, the hydroxyl group is attached to the second carbon atom (C2). In 2-methyl-2-propanol, the hydroxyl group is attached to a tertiary carbon atom. Finally, in 1-methyl-1-propanol, the hydroxyl group is attached to a primary carbon atom, but the carbon chain is shifted by one carbon atom. Due to these different arrangements, butanol has four isomers.