1. n-Butanol (1-butanol)
```
H H H H
| | | |
H - C - C - C - C - O - H
| | | |
H H H H
```
2. sec-Butanol (2-butanol)
```
H H H
| | |
H - C - C - C - O - H
| | |
H H CH3
```
3. Isobutanol (2-methyl-1-propanol)
```
H H
| |
H - C - C - C - O - H
| | |
H CH3 H
```
4. tert-Butanol (2-methyl-2-propanol)
```
H
|
H - C - C - O - H
| |
H CH3
/ \
CH3 CH3
```
These structural formulas show the arrangement of atoms within each molecule. You can see the differences in the position of the hydroxyl group (OH) and the placement of the methyl groups (CH3).
