Biochemistryy hellpp plleeasee

im tryna do this exam question, its asking for how many hydrogen atoms are present in ADENINE, and then shows a diagram of the actual base its self.
There is no mark scheme, but Google says theres 5 hydrogen atoms.. is this correct????

Reply 1

George H.

Adenine is at the end of the A-Level Chemistry data booklet.

https://www.a-levelchemistry.co.uk/uploads/9/0/4/5/90457821/aqa-7405-sdb_2.pdf

I count 3 visible hydrogens and 2 hidden ones because it's a skeletal formula, so yes 5 is correct.

Reply 2

m2105

thanks so much!! but what do you actually mean by the hidden ones from the skeletal formula?
Sorry lol i didn't Alevel Chemistry, but Biochem is one of my uni modules

(Original post by George H.)Adenine is at the end of the A-Level Chemistry data booklet.

https://www.a-levelchemistry.co.uk/uploads/9/0/4/5/90457821/aqa-7405-sdb_2.pdf

I count 3 visible hydrogens and 2 hidden ones because it's a skeletal formula, so yes 5 is correct.

Reply 3

George H.

Sorry I didn't make it clear.

The 3 visible hydrogens are the ones bonded to the nitrogens.
The 2 hidden ones are in the rings, attached to the carbons with only 3 visible bonds. As they have less than 4 visible bonds, it can be assumed that they are bonded to a hydrogen to make it up to 4 bonds.