Linhart — Hydrolysis of Alkyl Metallic Sulphates. 287 



MKS0 4 + MOH = MJSO, + KOH, if M has a valence of 

 one, and M(RS0 4 ) 2 + M(OH) 2 = 2 MS0 4 + 2ROH, if M has 

 a valence of two. 



This is plainly a reaction of the second order leading to the 

 mathematical expression 

 dx 



—rr~ = K (A — i x) (B — i x), where A, B, and x are all 



expressed in gram equivalents per liter, A and B denoting the 

 initial concentrations of the reacting substances respectively 

 and x the barium sulphate precipitated in time t. On inte- 

 gration the above equation gives for the velocity constant 



K = 2x2 ' 3 w (A-i«QB 



(A-B)t ft (B-iaj)A 



A — i x and B — i x are used instead of A — x and B — x 

 since for every gram equivalent of ester or base transformed 

 there are formed two gram equivalents of sulphate. 



Experimental Part. — For the saponification of the ethyl 

 sodium sulphate, silver tubes about 12 cm in length and of about 

 40 cm3 capacity were used. These tubes were placed in glass 

 tubes which fitted loosely over them. The glass tubes were 

 then constricted at about one inch above the top of the silver 

 tube to a size just large enough to allow a finely drawn out 

 tube to go through and the displaced air to escape. This 

 drawn out tube was connected by means of a piece of rubber 

 tubing to a burette which was attached to a bottle containing 

 the C0 2 free sodium hydroxide. Each silver tube was pro- 

 vided with a flat coil of fine platinum wire, the inner end of 

 which was bent upwards and projected about a half inch out 

 of the mouth of the silver tube. After 10 cm ' d of 0*6N ethyl 

 sodium sulphate were introduced by means of a carefully cali- 

 brated pipette, and also 10 cm3 of the C0 2 free sodium hydroxide 

 from the burette by means of the drawn out tube connected 

 with it, the projecting platinum wire was grasped with a 

 pair of long pincers and slowly moved up and down until 

 the two dissolved substances were well mixed. The tubes 

 were then sealed, cooled and submerged in the thermostat at 

 60°. A thin piece of cork had to be placed between the walls 

 of the silver and the glass to keep the top of the silver tube 

 from touching the glass. This was found necessary as the 

 liquid, although about 4 cm from the top, would gradually rise 

 after being in the thermostat for several days and attack the 

 glass if the silver tubes were allowed to lean against it. 



Before treating the sodium sulphate resulting from the 

 saponification of the ethyl sodium sulphate by the sodium 

 hydroxide, with a solution of barium chloride which had to be 



