mixed Salts of Potassium and Sodium. 133 



the quantity producible by chloride of sodium above the 

 quantity producible by chloride of potassium ; this additional 

 quantity of chloride of silver being equal to 0*52201 multi- 

 plied by every unit of chloride of sodium present in the 

 mixture. 



Wherefore, 



In Operation c, we multiply the mixed chlorides by r9240'l' 

 to find the quantity of chloride of silver producible by the 

 given weight of chloride of potassium alone. 



In Operation d, we subtract this quantity from that of the 

 chloride of silver actually produced in experiment b, by the 

 mixed alkaline chlorides ; and thus determine the amount of 

 the excess produced by the chloride of sodium. 



In Operation e, we divide this excess by 0*52201 to ascer- 

 tain the number of units, or the weight, of the chloride of 

 sodium contained in the mixture. 



Tables of Data. — 1. To find the weight of the components 

 and equivalents of any quantity of chloride of sodium, multi- 

 ply it, 



by 0*39656 for the sodium it contains. 

 0*60344? for the chlorine. 

 0*53289 for its equivalent of soda. 

 And by 2*44'605 for the quantity of chloride of silver which 

 it produces by precipitation. 



2. To find the weight of the components and equivalents 

 of any quantity of chloride of potassium, multiply it 

 by 0*52534- for the potassium it contains. 



0*47466 for the chlorine. 



0*63257 for its equivalent of potash. 



And by 1*92404 for the quantity of chloride of silver which 

 it produces by precipitation. 



These tables explain the reason why a greater quantity of 

 chloride of silver is produced by chloride of sodium than by 

 chloride of potassium. The reason is that chloride of sodium 

 contains 60 per cent, of chlorine, while chloride of potassium 

 contains little beyond 47 per cent. I point out this fact, be- 

 cause it shows the sort of differences upon which all indirect 

 analyses must be founded. 



Example. — In the analysis of a mineral that contains both 

 potassium and sodium we have proceeded so far as to have 

 nothing to separate but these two metals, which are present 

 in the condition of chlorides. 



a. The mixture of chlorides weighs 5 grains. 



b. It produces by precipitation 11*18623 grains of chloride 



of silver. 



