Can i use the iodoform test to distinguish btw ketones and aldehydes?
The iodoform test or iodoform reaction is a qualitative chemical test for the detection of ketones and aldehydes carrying an alpha methyl group. The reagents are iodine and sodium hydroxide. Only methyl ketones, or alcohols with the feature: CH3CH(OH)-R may undergo this reaction. There are three steps to the iodoform reaction when starting from an alcohol. If the reaction starts from a methyl ketone, the first step is not needed. Addition of I2(aq) (usually I2 dissolved in KI, shown here reacting with 2-propanol) 2 NaOH + I2 + CH3CH(OH)CH3 → 2 NaI + CH3COCH3 + 2 H2O oxidizes the hydroxyl group to a ketone, The ketone formed reacts with the I2(aq) in a substitution reaction to produce a triiodoketone, for example triiodoacetone. CH3COCH3 + 3I2 → CH3COCI3 + 3HI (Thus, ketone and aldehyde with structure -COCH3 also show positive results). Ethanal is the only aldehyde to give the iodoform reaction. Finally, OH- (aqueous) is added, which reacts with, for example, the triiodoacetone. CH3COCI
