588 



PROFESSOR DITTMAR AND MR JOHN M' ARTHUR ON 



Reducing to unit weight of chloroplatinate 



Platinum. 



Total Chlorine. 



Fixed Chlorine 



0-40203 



0-43639 



0-14587 



040179 



0-43662 



lost 



0-40191 



043650 



(0-14587) 



second analysis miscarried, 

 analysed we had — 



L, ... 



II., . . . 



Mean* 



* Or reducing to 2KC1 parts, 

 Chloroplatinate. Platinum. Loose Chlorine. 



48610 195-37 141-28=3-9847x01 



The water was determined directly in 3 '2310 grms. : found 5*9 nigs., or 

 01826 per cent., or 0*888 parts per M parts of chloroplatinate. Substituting 

 01534 x 17 of hydroxyl for the chlorine deficit, we have — 



{ 



Platinum, 



K 2 C1 2 , 



3-98466 x CI, . 



0-01534 x£0, • 

 001534 xJH 2 0, 



Other water, by analysis, 



Total, 



M., 



195-37 



14918 



141-28 



012 



014 



0-75 



486-84 

 48610 



0-888-0138: 

 0-750 



Excess of analysis, = 074 



which is not too much. 



It is surprising to see that the action of the hydrochloric acid did not 

 resubstitute CI for all the (OH) of the recrystallised salt. 



The following table summarises what we found regarding the quantity of 

 platinum (" Pt ") present, per 2KC1 parts, in our several chloroplatinates : — 



1. Chloroplatinates prepared by Simple Precipitation ; Platinum moderately (if at all) 



in excess. 



Experiments. 



p.* 



I. 



209 



II. 



218 



III. 



206 



IV 



214 



V. 



195 



Va. 



203 



VI. 



196 



Volume of mixture of Reagents 

 per 1 grm. of KC1 used. 



Mixture evaporated to small 

 volume, then alcohol added, 



32 c.c. 



32 „ 



34 „ 



50 „ 

 (Precipitated by alcohol.) 



Pt. 





196-28 - 





195-67 





19567 



Mean 



195-79 



[ Pt = 



196-64 



196-23 



196-58 





19695 j 





* " P " stands for weight of platinum used as chloroplatinic acid, per 2KC1 parts. 



