34 P. T. Clevk, 



Chromate of samarium and potassium 



SmK2Cr04+3H20. 



A solution of bichromate of potassium is not precipitated by ni- 

 trate of samarium, but a solution of the neutral Chromate is. A bulky 

 yellow precipitate is thrown down which soon settles down as a cry- 

 stalline powder of the double salt. As it is decomposed by washing 

 with water, it was taken from the filter and freed from the solution 

 by pressure only. The salt of samarium was in excess. 



1.6367 gram lost by 100° 0.0880 gram and on heating nearly to 

 redness a further loss of 0.0165 gram or in all 0.1045 gram HgO. On 

 dissolving in nitric acid and precipitating with mercurous nitrate, a precipi- 

 tate was obtained which yielded on ignition 0.5387 gram CrsOs. From 

 the filtrate, freed by HaS from mercury, 0.6415 gram SmgOj was thrown 

 down with ammonia. The filtrate from the samarium-hydroxide gave 

 0.3335 gram K2SO4. 



In percent: " „ , 



' Calc 



By saturating boiling dilute formic acid with oxide of samarium 

 a white, heavy, crystalline powder, very slighly soluble in water, is 

 produced. 



0.4062 gram gave on evaporation with dilute sulphuric acid 0.4206 

 gram Sm2 3S04. 



In percent: 



I 



Calc 



Sm^Os 61.28 174 61.05 



C2H2O3 (38.72) HI 38.95 



100.00 285 100.00 



