R-OH + H2O <-> R-O- + H3O+
H-OH + H2O <-> H-O- + H3O+
At one time, a small number of water molecules donate H+ ions to other water molecules = behaves as a weak acid.
With phenols, the equilibrium lies further to the right so it is more acidic than water.
Ethanol < water < phenol < carboxylic acids
The stability of the R-O- formed determines how strong the acid is and where the equilibrium lies.
If the negative charge on the O atom can be shared with other atoms it will be more stable.
If the R-O- is derived from a phenol or carboxylic acid the charge gets spread out - delocalisation.
Phenols and carboxylic acids can react with strong bases to form salts. (React with NaOH to form their sodium salts)
The Iron (III) Chloride test & Ester formation
Iron (III) Chloride is test for phenol and its derivatives
The enol group (-C=C-OH) reacts with the Fe3+ ion to form a complex
Alcohol + Carboxylic Acid <-> Ester
Concentrated Sulphuric of Hydrochloric acid must be added to speed up reaction & heated
Can be made using phenols instead of alcohols (& use acyl chloride or acid anhydride instead of carboxylic acid)
Salicylic Acid > esterify the -OH group --> Aspirin (soluble in water/absorbed into bloodstream)
Salicylic Acid > esterify the -COOH group --> Oil of wintergreen (soluble in fat/absorbed through skin)