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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: spythebeast on January 04, 2006, 12:10:28 PM

Title: why is aspirin more soluble in ethanol than in water?
Post by: spythebeast on January 04, 2006, 12:10:28 PM

Hi, can anyone answer this for me:

why is aspirin more soluble in ethanol than in water?

Thanks!

Title: Re:why is aspirin more soluble in ethanol than in water?
Post by: plu on January 04, 2006, 05:23:40 PM

The aspirin molecule is made up of a benzene ring, a carboxyl group, and an ester.  It has both polar and non-polar components.  Thus, the affinity of water (very polar) for this compound is not as great as the affinity of water for itself.  However, the affinity of ethanol molecules (only slightly polar) for aspirin molecules is relatively similar to the affinity of ethanol molecules for each other.  Thus, aspirin is more soluble in ethanol than in water.