62 P. 0. 'Ra.j'—Chemical Examination of [No. I, 



N 

 4!'95 0. c. -^ HCl were required to neutralise the excess of alkali. 



N 

 (20'7 — 4-95) c. c. or 15'75 c. c. -^ HCl represent the amount of alkali 



required for the saponification of the oil. 



1 c. c. § HCl = 002805 gm. KOH 



Amount of potash consumed by 1,000 gm. oil { — saponification. 



.,,,.,,, ,, 15-75 X 002805x1000 _ . ^ 



equivalent), is therefore equal to o^tiol gm. = 174*6 gm. 



2. 1"7J3 gm. oil were heated in a flask over a water-bath for ten 

 minutes with 20 c. c. KOH solution, the mouth of the flask being covered 

 by a watch-glass — 



20cc. KOH = 20-7 c.c. -^r HCl (Blank experiment) 



N 

 10* 1 c. c. -^-HC 1 were required by the excess of potash. 



a 



-c .' • 1 . 10-6 X 00 2805x1000 ,^^ , 

 Saponification equivalent = „ — = 173"5 



3. Mustard oil expressed from a different sample of seeds. 



3-084 gm. oil were treated with 20 c. c. KOH solution in a 



bottle, which was immersed in boiling water for about 40 minutes ; the 



mouth of the bottle being closed by an India-rubber cork tied down by 



means of wire — 



N 

 20 c. c. KOH = 208 c. c. - HCl (Blank titration) 



N 

 1'5 c. c. -^ HCl were required for the excess of potash. 



N 

 or I9'3 c. c. -jr HCl represented the amount of alkali used up. 



u 



.n .- • , . 19-3 X 0-02805x1000 ,^_ 

 Saponification equivalent = q7)al ~ 175'o 



4. 2*222 gm. oil were treated with 20 c. c. KOH solution and heated 



in a flask over a water-bath for 12 minutes ; the mouth of the flask being 



covered with a watch-glass — 



N 

 Excess of alkali required 7 c. c. -^ HCl 



20c.c. KOH „ 20-8 „ „ (Blank titration). 



.^ ,. . , , 13-8x002805x100 ,„, „ 

 Saponification equivalents q-o-t ^ =174*2 



