H. D. Newton — Volumetric Estimation of Titanium. 131 



Measured portions of these solutions were drawn into a flask 

 of about 100 om3 capacity, a definite amount of zinc having a 

 known iron content was added, the solution finally made up to 

 such volume as to contain about ten per cent of concentrated 

 sulphuric acid, this strength of acid being sufficient to hold the 

 titanic acid in solution and yet be without oxidizing action on 

 the reduced oxide. A rubber cork, through which passed a 

 delivery tube and small separating funnel, was inserted into 

 the mouth of the flask. Gentle heat was applied, while an 

 atmosphere of hydrogen was constantly kept above the liquid 

 until all the zinc was dissolved and the solution cooled, a pro- 

 cess which generally took about an hour. An excess of ferric 

 sulphate was passed through the separating funnel and fol- 

 lowed at once by cold, fresh]} 7 distilled water until the flask 

 was filled to the neck. The contents of the flask were then 

 poured into a liter flask containing more cooled distilled water 

 and the whole immediately titrated with tenth-normal potas- 

 sium permanganate. 



In the following table are given results obtained by the fore-' 

 going procedure. In table No. II are recorded similar exper- 

 iments in which larger amounts of titanic acid were taken. 







Table I. 







Titanium 





Ti0 2 



Ti0 2 





sulphate 



KMn0 4 



taken 



found 



Error 



cm 8 



cm 3 



grm. 



grm. 



grm. 



30 c.c 



6.50 



0-0520 



0-0523 



+ 0-0003 



30 



6-52 



0-0520 



0-0524 



+ 0-0004 



30 



6-45 



0-0520 



0-0519 



— 0-0001 



30 



6-50 



0-0520 



0-0523 



+ 0-0003 



30 



6-48 



0-0520 



0-0521 



+ 0-0001 



30 



6-42 



0520 



0-0518 



— 0-0002 



30 



6-50 



0-0520 

 Table II. 



0-0523 



+ 0-0003 



Titanium 





Ti0 2 



Ti0 2 





sulphate 



KMnOi 



taken 



found 



Error 



cm 3 



cm 3 



grm. 



grm. 



grm. 



25 C.C 



1995 



•1596 



•1599 



+ 0-0003 



25 



19-93 



•1596 



•1598 



+ 0-0002 



25 



19-95 



•1596 



•1599 



+ 0-0003 



25 



19-90 



•1596 



•1595 



—o-oooi 



25 



19-95 



•1596 



•1599 



+ 0-0003 



25 



19-95 



•1596 



•1599 



+ 0-0003 



25 



19-90 



•1596 



•1595 



—o-oooi 



25 



19-85 



•1596 



•1591 



— 0-0005 



25 



19-95 



•1596 



•1599 



+ 0-0003 



25 



19-88 



•1596 



•1594 



— 0-0002 



25 



19-95 



•1596 



•1599 



+ 0"0l)03 



25 



19-95 



•1596 



•1599 



+ 0-0003 



