as the Acid Sulphates, etc. 



303 



The results given in Tables III and IV, in which the sodium 

 and potassium salts are calculated as pyrosulphates, are suffi- 

 ciently satisfactory for purposes of quantitative estimation. 



As in the case of the caesium and rubidium salts, a number 

 of determinations as the neutral sulphates were made by igni- 

 tion of the sodium and potassium pyrosulphates with results 

 which are recorded. In Table Y two determinations are 

 recorded, in one of which the caesium and rubidium salts 

 were treated together, and in the other the sodium and 

 potassium salts. An application of this same general method 











Table II. 













RbHS0 4 







Rb 3 S0 4 









RbCl 



calcu- 



RbHS0 4 





calcu- 



Rb 2 S0 4 







taken. 



. lated. 



found. 



Error. 



lated. 



found. 



Error. 





grm. 



grm. 



grm. 



grm. 



grm. 



grm. 



grm. 



1 



0-1252 



0-1889 



0-1878 



o-ooii — 









2 



0-1212 



0-1829 



0-1840 



0-0011 + 



0-1460 



0-1460 



0-0000 + 



3 



0-1230 



0-1856 



0*1850 



0-0006 — 









4 



0-1230 



0-1856 



0-1858 



0-0002 + 



0-1357 



0-1350 



0-0007 — 



5 



0-1610 



0-2430 



0-2416 



00014 — 



0-1777 



0-1772 



0'0005 — 



6 



0-1360 



0-2052 



0-2032 



0-0020 — 

 Table III. 



0-1501 



0-1490 



o-ooii — 





KC1 



K 2 S a 7 







K 2 S0 4 

 calcu- 



K 2 S0 4 







calcu- 



K 2 S 2 T 







taken. 



lated. 



found 



Error. 



lated. 



found. 



Error. 





grm. 



grm. 



grm. 



grm. 



grm. 



grm. 



grm. 



1 



0"2172 



0-3704 



0-3698 



0-0006 — 









2 



0-17C6 



0*2909 



0-2886 



0-0023 — 



01 993 



0-1972 



0-0021 — 



3 



01192 



0-2032 



0-2022 



o-ooio— 



0-1393 



0-1381 



0-0012 — 



4 



0-1074 



0-1830 



0-1823 



0-0007 — 









5 



0-1096 



0-1868 



0-1860 



0-0008 — 









to a lithium salt gave no evidence of the existence of a stable 

 acid sulphate or pyrosulphate. The results may be summed up 

 as follows : Caesium and rubidium salts of volatile acids when 

 treated with sulphuric acid in excess and brought to a constant 

 weight at a temperature between 250° C. and 270° C. form 

 acid salts of the type K,HS0 4 and the neutral salts of the type 

 R 2 S0 4 on ignition. Some tendency of the caesium salt to hold 

 more sulphuric acid than corresponds to the formation of the 

 acid sulphate RHS0 4 was apparent at temperatures between 

 250° C. and 270° C, but upon raising the temperatures above 

 300° C. the loss was excessive and showed a tendency on th 

 part of the acid sulphate, at this temperature, to pass towarfU 

 the condition of the pyrosulphate. Sodium and potassium 

 salts when heated under the conditions described give pyro- 

 sulphates of the type R 2 S 2 7 which on ignition go into the neutral 



