A level chemistry question

Can I write...
2- pentanol or do I have to write pentan-2-ol
and
Can i write...
2- Pentene or no i have to write Pent-2-ene

Reply 1

StoickTheVast

The IUPAC names for those would be pentan-2-ol and pent-2-ene. Although they're not wrong, it's better if you get into the habit of writing their IUPAC names (since they are what questions usually ask for).

Reply 2

Kallisto

Entertainment Forum Helper

Original post by JJK456

Can I write...
2- pentanol or do I have to write pentan-2-ol
and
Can i write...
2- Pentene or no i have to write Pent-2-ene

I was taught to write the numbers in the middle of the names to make clear where the functional groups or C=C-double bonds in the organic substance are and which C-atom is connected to, so

Pentan-2-ol and Pent-2-ene

(edited 2 years ago)

Reply 3

ashvinsingh

Original post by JJK456

Can I write...
2- pentanol or do I have to write pentan-2-ol
and
Can i write...
2- Pentene or no i have to write Pent-2-ene

Pentan-2-ol and pent-2-ene as the number indicates the position of the functional group, pentan-2-ol indicates the hydroxyl group is bonded to the second carbon.

Reply 4

_Rusty_

Volunteer Team

Original post by ashvinsingh

Pentan-2-ol and pent-2-ene as the number indicates the position of the functional group, pentan-2-ol indicates the hydroxyl group is bonded to the second carbon.

Yes this is exactly right because imagine if you had a more complicated molecule which had more numbers

Reply 5

Kallisto

Entertainment Forum Helper

Original post by ashvinsingh

Pentan-2-ol and pent-2-ene as the number indicates the position of the functional group, pentan-2-ol indicates the hydroxyl group is bonded to the second carbon.