Aldehydes, ketones, and esters revision sheet

Mathsandscience.net Aldehydes, Ketones, and esters CH3CH2OH +[O] g CH3CHO +H2O CH3CHO +[O] g CH3COOH Primary alcohol g Aldehyde Aldehyde Carboxylic Acid A secondary alcohol will form a ketone but NOT a carboxylic acid Conditions pottasium dichromate and H2SO4 (turns from orange to green) reduction reverses the process turning the aldehyde and ketone to an alcohol (need NaBH4). Testing for C=O is 2,4,DNP mixed with methanol and H2 SO4 is called Brady reagent. Forms a orange ppt. Differentiate Aldehyde or ketone use Tollens , aldehyde oxidised and Ag produced (silver mirror) Identifying C=O purify the orange ppt and check Melting point hept-2-one = 90oC : Cyclohexanone = 162oC : Octan-2-one = 58oC Carboxylic Acids CH3COOH + Na g CH3COONa+ +1/2 H2 CH3COOH +KOHg CH3COOK+ + H2O 2CH3COOH + Na2CO3g 2CH3COONa+ + CO2+ H2O Esters O O CH3 C + HO CH2 g CH3 C + H2O OH O CH3 Acid hydrolysis under reflux using dilute sulphuric or dilute hydrochloric as a catalyst. Alkaline Hydrolysis uses dilute sodium hydroxide under reflux and is irreversible Esters are used for perfumes and flavourings. Copyright 2010 Tutoring for AS and A2 Mathsandscience.net C C H HH H O C C HH H :H- C HH :O- H H H HO H H OH + OH-2SO4 used as CATALYST