282 



METHODS OF IDENTIFICATION AND STUDY 



Use a rose-top burner to minimise the danger of 

 cracking the flask; and to the same end, well agitate 

 the contents of the flask to prevent the chalk settling. 



The distillate "A" will contain alcohol, etc. (vide 

 page 285) ; the residue "a" will contain the volatile 

 and fixed acids. 



4. Disconnect the flask and filter. The residue "a" 

 then = filtrate B and residue b. 



FIG. 152. Arrangement of distillation apparatus for acids, etc. 



5 . Residue b. Wash the residue from the filter paper, 

 dissolve by heating with dilute hydrochloric acid, and 

 add calcium chloride solution and ammonia until 

 alkaline. 



White precipitate insoluble in acetic acid = oxalic 

 acid. 



6. Make up filtrate B to 500 c.c. with distilled water 

 and divide into two parts. 



