What does organic mean?

[Meredith92]

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This comes from a passage in TBR
Which of the following pigments will decompose first?
A Alizarin (chemical formula= 1,2-dihydroxyanthraquinone)
B Azurite (chemical formula= 2 CuC* 3 Cu (OH)2 )
C Rust ( Fe2O3*nH2O)
D Verdigris (Cu(C2H3O2)2*Cu(OH)2)


In the passage it says" As a rule, inorganic pant pigments last for a far longer period of time than the organic pigments" The answer key says A is correct. They say inorganic pigments are already oxidized, so they should remain air-stable for some time. the organic pigments can oxidize in air, so they dont last long. The only organic compound among the choices is 1,2-dihydroxyanthraquinone. Note that organic pigments contain conjugated pi-networks and are found in oil based paints

I thought something is an organic molecule if it contains carbon, but clearly that definition does not apply here. How did they determine which was organic? Are they defining it based on this conjugated pi network they mention??

Thanks for your help!

 

[DrEnderW]

In simplistic terms for the MCAT, organic would mean a molecule composed of a carbon backbone with hydrogen and possibly oxygen atoms attached.

The answer is obviously A because the bottom 3 choice all have metal atoms in the molecule. Answer choice A does not and is an organic molecule.

Hope that helps. GL!

 

[Meredith92]

So just having carbon doesnt make something organic? you also cannot have any metal atoms?
(thanks for your help!)