[cherrybarry]

when there is a functional group in the 1 position and no others of the same in the molecule, can be leave off the 1 prefix in the name?

For example, is 1-propanol the same as just propanol? Is the 1 implied in this case or must it be added?

[Teddy]

As far as I understand, I believe you must name where the functional group is positioned for chains propane and larger. In the example of 1-propanol, you could possibly have the hydroxyl group on the second position making it 2-propanol. This is why you must state where it is.

[jwesterway]

The number is required when multiple options are possible.
For propanol there can be 1 or 2 propanol, alternativly you can use n-propanol instead of 1, and iso-propanol instead of 2. Without the number or letter prefix how is someone to know by looking at a bottle labeled propanol if it contains 1 or 2 propanol?

-Josh

[Albert]

Far from being a rule, it is a common habit to call 1-propanol just propanol.

[Alberto_Kravina]

Isn't the new nomenclature Popan-1-ol and Propan-2-ol ?

[Garneck]

1-propanol and propan-1-ol are both correct names..

[movies]

1-propanol and propan-1-ol are both correct names..

Both are okay when there is just one functional group.  If there is more than one then you must use the latter version to define which FG you are assigning the position to.