TRANSFORMATION OF NITROAMINES AND ALLIED SUBSTANCES, 119 
Il. Hydrolysis of Acetic Anhydride. (With Martan Jones, B.Sc.) 
- So far the hydrolysis of acetic anhydride has only been investigated 
in aqueous solution by Menschutkin and Vasilieff, Lumiére and Barbier 
(these investigators used a titrimetric process), and Rivett and Sidg- 
wick ® (using the change of electric conductivity). With the aid of the 
method above described, it is possible to follow this reaction in various 
media, and in the presence of catalysts. 
(i) Hydrolysis in Aqueous Solution.—The table shows typical results 
of experiments when three different methods of measurement are used. 
TABLE I. 
Lumiére and Barbier Rivett and Sidgwick Orton and Jones 
A iY A ka he A me 
0-491 0°0735 0°487 0°1383 0-074 0-486 0-074 
0°265 0°1484 0:0793 0-269 0:084 
0-058 0°1561 0°0835 
0:491 17°=0-03 0°495 kt =0°028 
On the supposition that the reaction is represented by the equation : 
Ac,O -+ H,O = 2CH,.CO,H, the velocity factor, k; = the product of 
the velocity co-efficient, /,, of this reaction of the second order, and 
the concentration of the water, which is perceptibly constant, 
where A is the initial concentration of the anhydride in moles, and x the 
amount changed in time ¢ (minutes). 
(ii) Effect of Medium.—Table II. shows the effect of the composition 
of the medium on the rate of hydrolysis. 
Tasre II. 
: Concentration of |Velocity-coefficient 
Medium Temperature | Acetic Anhydride | or Velocity-factor 
Glacial acetic acid . 16 0-0804 11= 0°00042 
([H,0]=0°18) 
95 per cent. acetic acid . 16 0:0782 k,=0-001 
90 oe a5 16 0-0815 0:0028 
80 a5 A 16 0:0813 0:0056 
50 “ “ 15 0-083 0-016 
Water ser tPctr eeiatbcteyy y ~ 6 15 0-473 0-074 
95 per cent. aqueous acetone 15 0-087 6% hydrolysed 
in 118 hrs. 
50 = “ 15 0-088 k,=0-006 
Acetic anhydride . . 15 10°3 k31:—0-000071 
((H,0]=1°8) 
8 Trans, Chem, Soc., 1910, 97, 733, 1677, 
