how can this be ? help me out chemists

[hendrix62892]

ive been doing some research and found that cocaine and scoplamine have the same empirical formula,how can that be possible ?

C18H21NO4

 

[pallidamors]

lots of chemicals have the same empirical formula but different effects. how those molecules are arranged in three dimensions determines their effects to a greater extent than their formula.

 

[ikkyu]

Same formula, yes, but the molecular structures are different:

http://www.erowid.org/psychoactives/chemistry/chemistry_compare.php?lm=cocaine_2d&rm=scopolamine_2d

 

[Solipsis]

yep, the empirical formula is nothing but a sum of the buildingblocks. However, the arrangement of those building blocks is essential to the identity of the compound.
For instance you and I might be made up of the same sum and quantity of a certain list of atoms, but since we are built in different patterns we are not really alike.