TANTALUM. 



237 



was ignited and weighed as Ta 2 5 . 100 parts of the salt gave the follow- 

 ing quantities of Ta 2 O 5 and K 2 S0 4 : 





56.50 

 56.75 

 56.55 

 56.56 



Mean, 56.59, .037 



44-37 

 44-35 

 44.22 

 44.24 



Mean, 44.295, .026 



From these figures, 100 parts of K 2 S0 4 correspond to the subjoined 

 quantities of Ta 2 5 : 



127.338 

 127.960 

 128.178 

 127.848 



Mean, 127.831, .120 



The ammonium salt, (NH 4 ) 2 TaF 7 , ignited with sulphuric acid, gave 

 these percentages of Ta 2 O 5 . The figures are corrected for a trace of K 2 SO 4 

 which was always present : 



63.08 



63.24 



63.27 



63.42 



Mean, 63.25, .047 



Hence we have four values for Ta : 



From potassium salt, per cent. Ta 2 O 5 Ta = 182.336 



From potassium salt, per cent. K 2 SO 4 " 180.496 



From potassium salt, K 2 SO 4 : Ta 2 O 5 " 181.422 



From ammonium salt, per cent. Ta 2 O 5 " = 181.559 



Average Ta = 181.453 



'Or, if = 16, Ta = 182.836. 

 These values are computed with O 

 N = 13.935, and F = 18.912. 



15.879, K = 38.817, S = 31.828, 



