DERIVATIVES OF ALCOHOLS AND ACIDS 63 



CH3-C00(H + HO)-C2H5->CH3-COO-C2H5+H20 



Acetic acid Ethyl Ethyl acetate 



alcohol 



The sulphuric acid brings about the loss of the water in the above 

 reaction, (b) To a little of any salt of acetic acid, e.g. sodium 

 acetate, add a little dilute alcohol and then i c.c. of sulphuric acid. 

 Warm and note odor of ethyl acetate. The sulphuric acid first 

 reacts with the salt of acetic acid, forming free acetic acid. 



CHs-CGONa + HOSO2OH -> CH3-COOH + NaOSOaOH 

 Sodium acetate Acetic acid 



The free acetic acid then reacts with the alcohol in the presence of 

 sulphuric acid and forms the ester. 



(2) Hydrolysis, (a) Place 10 g. ethyl acetate (CH3COOC2H5), in 

 a flask and add 100 c.c. of 10 per cent sodium or potassium hydroxide. 

 Connect with a return condenser and boil until no odor of ethyl acetate 

 is noticeable. Change the condenser and distill off about 25 c.c. — 50 

 c.c. Test the distillate for ethyl alcohol as in Experiment VII, 4. 



(b) Place the remainder of the solution in the flask in an evaporat- 

 ing dish. Carefully neutralize excess of alkali with hydrochloric 

 acid, avoiding excess of acid by testing with litmus paper. Evapo- 

 rate to dryness. Test the dry salt for acetates as in (i), b. The 

 reactions involved are : 



CH3-COO-C2H5 + KOH -^ CH3-COOK + C2H5OH 



Ethyl acetate Potassium Alcohol j 



acetate 



CH3-COOK + H2SO4 -> CH3-COOH + KHSO4 



Acetic acid 



CH3-COOH + HO-C2H5 -> CH3-COO-C2H5 



Ethyl acetate 



EXPERIMENT STUDY XVI 



Fats and Soap 



(i) Saponification of a Fat. (a) Use 10 g. of lard, tallow, cotton- 

 seed oil or oHve oil. Place in an evaporating dish and add 200 c.c. of 

 5 per cent NaOH. Heat on water bath until all melted fat has dis- 

 appeared. Continue to heat until the liquid has evaporated; or 



