410 R. W. CHALLINOR. 



Go(N0 3 ) 2 solution placed in nessler glass and Ni(N0 3 ) 3 

 ran in till it was quite free from pink or green colour. 



Thus 2*56 cc. Go solution = '015 grams = 23*45°/° Oo 

 required 4*2 „ Ni „ ='01897,, = 76'55f° Ni 



•06397 

 It was then diluted to 50 cc. 



The method used in the first series of determinations 

 was as follows : — A solution containing a known weight of 

 the mixed metals as nitrates was given, colour noted, and 

 if accessary it was diluted to a definite volume and a 

 measured quantity taken, so that after titration the total 

 weight of mixed metals in solution would be about the 

 same as that ID the solution of standard tint. 



The nickel or cobalt solution of known strength was then 

 added from a buret t e till the colour was nearly neutralised, 

 then diluted to 50 cc. in the nessler tube, and finally brought 

 to same tint as standard by the addition of more nickel or 

 cobalt as required; they qow contained as nearly as possible 

 the same proportion of nickel and cobalt, and since the 

 amounts are known for the standard solution they may be 

 calculated for the other. 



Example — 



Weight of mixed metals in solution given = *05835 gm. 



Colour — pale green 

 Volume of Co(X0 3 )-> solution required to 



bring it to the standard tint = '45 cc. = '00263 gm. Oo 



Total mixed metals in 50 cc. = '06098 gm. 

 The standard contained 76'55) ,j Xi 



• Q6Q98 x 76 ' 55 = -04668 Ni 

 100 



Ni + Co = '05835 

 Ni found = '04668 



Co = '01167 



