Samarium. 39 



Citrate of samarium '' 



SmC;,H4(OH)(CO,)3 + 6 (at 100» dried 1) H^O. 



Citric acid gives with acetate of samarium a white, bulky, not 

 crystalline precipitate. The salt is soluble in ammonia, and the solution 

 remains clear on boiling. 



The salt pressed between filter-paper lost on heating to 100" 21.48 

 percent water corresponding to 5 mol. HgO (calc 20.13). 



0.3828 gram salt, dried at 100°, gave by ignition 0.1877 gr. SrajOs. 



In percent: 49.03. The formula with IHgO requires 48.74 percent. 



Picrate of samarium 



Sm3C6H2(N02)30 + 8H2 0. 



A solution of picric acid dissolves the oxide of samarium on boi- 

 ling. The intensely yellow solution yields after concentration a heavy 

 orange coloured oil, which on farther evaporation over oil of vitriol 

 dissolves. Later on the salt crystallises in small yellow needles, which 

 are easily soluble and melt below 100°. When strongly heated the salt 

 explodes. The salt loses at 100° 11.83 percent HgO or 6 mol. H^O, 

 calc 11.04. 



0.7312 gram of the crystallised salt was dissolved in water and 

 precipitated with an alcoholic solution of oxalic acid. On ignition 0.1308 

 gram Sm^Oj was obtained. 



In percent: 17.89 SmgOj, calc 17.79. 



Spec. Gravity: 



0.6538 gram, temp. 18°.5, sp. Gr. 1.954. 



