1. Solubility Like dissolves like Organic compounds are not expected to be soluble in water Rule of Thumb: C/O ratio

2. However, If the organic compound can be ionized It is more likely to be water-soluble Requirement: the presence of an ionizable atom/group since ionic compounds are polar, and thus water-soluble What is an ionizable atom/group one which can form a conjugate acid or conjugate base upon treatment with an acid or base

3. Classification of Organic Compounds from a solubility point of view will be soluble upon reaction with Examples basicacid (HCl –aq)Amines weakly acidicstrong base (NaOH –aq)Phenols strongly acidicweak base (NaHCO 3 –aq)Carboxylic Acids neutralstrong acid (H 2 SO 4 –conc)Alcohols, Aldehydes, Ketones, Esters, etc inertalways insolubleNo ionizable FG e.g. alkyl halides

4. will be soluble upon reaction with Examples basicacid (HCl –aq)Amines

5. will be soluble upon reaction with Examples weakly acidicstrong base (NaOH –aq)Phenols

6. phenolate But

7. Phenols have very different acid-base properties compared to alcohols phenolate a phenolate, the conjugate base of a phenol, is much more stable than an alkoxide alkoxide the conjugate base of an alcohol

8. extensive charge delocalization into the aromatic ring no charge delocalization here

9. extensive charge delocalization into the aromatic ring electron/charge delocalization is a stabilizing factor more stable weaker conjugate base the conjugate base of a stronger acid is a weaker conjugate base thus a phenols is a stronger acid than an alcohol

10. will be soluble upon reaction with Examples strongly acidicweak base (NaHCO 3 –aq)Carboxylic Acids

11. will be soluble upon reaction with Examples neutralstrong acid (H 2 SO 4 –conc)Alcohols, Aldehydes, Ketones, Esters, etc all insoluble with water if C/O ratio > 4 not strongly basic enough to ionize in the presence of NaOH (aq) ( remember why not ) But oxygen will protonate upon treatment with H 2 SO 4 (conc)

12. will be soluble upon reaction with Examples neutralstrong acid (H 2 SO 4 –conc)Alcohols, Aldehydes, Ketones, Esters, etc

13. will be soluble upon reaction with Examples inertalways insolubleNo ionizable FG e.g. alkyl halides

14. Samples to be tested N-ethylaniline  -naphthol (a phenol) benzoic acid butanol para -dichlorobenzene