[INeedSerotonin]

Hello

I've come across this exercise about the citric acid.



The exercise asks me to tick the correct propositions:

I - It has a good solubility in water and alkaline compounds;
II - It has only one chiral carbon;
III - It is a tricarboxylic acid.

I've painted in purple what I believe to be a chiral carbon. It seems to me that it would be so, because the OH and the C=O on both sides, right and left, of the purple dot are not "cis", they're "trans" (I think that terminology doesn't fit here, but, well, you guys understand me). So the right side is not the same as the left side.

What do you guys think about it?

The exercise also tells me (III) is false, but according to my research that's not the case. So perhaps that could be a printing error.

Could you guys please shed some light here?

Thank you

[AWK]

Citric acid has two identical substituents -CH2COOH. What does this mean for chirality?

[INeedSerotonin]

Citric acid has two identical substituents -CH2COOH. What does this mean for chirality?

So the way the COOH is disposed is just misleading? It doesn't really matter if we put the OH or the C=O facing north or south?

I remember my teacher telling me that the sigma bonds in the molecule can just "rotate", but I wasn't sure if that applied here.

[Borek]

https://en.wikipedia.org/wiki/Asymmetric_carbon

Please read the very first phrase.

[Fish200398]

for me 1 and 3 are true

this compound has total 3 COOH compound aka carbocylic acid.

this short chain COOH soluble in water, also alkyl hydroxyl aka alcohol aka OH is soluble in water since forming hydrogen bonding with water.

there're 2 chiral carbon. you can check the link Mr Borek given.

cmiiw

[chenbeier]

No, there are no chiral atoms. For chirality  you need 4 different substituents.  Citric acid has only 3 at the middle C atom.

[Fish200398]

ok there's no chiral. i was mistaken

[INeedSerotonin]

Thank you, guys

What confused me the most was the way it was represented. But I understand now.