SIR WILLIAM CROOKES ON SCANDIUM. 31 



Theory. Experiment. 



Sc 44-10 26-07 26-57 



(HCOO) 2 . . . 



OH ^125-04 73-93 73'43 



H 2 O 



169-14 100-00 100-00 



SCANDIUM ACETATE, 

 ,211,0. 



Scandium oxide after ignition does not dissolve in acetic acid. The hydroxide, 

 however, dissolves easily, and the acetate soon separates from the liquid in the form 

 of fine white crystals, difficultly soluble in water. The aqueous solution, evaporated 

 over the water-bath, deposits hard crystalline crusts. 



When freshly prepared, the acetate dried in the air has the composition given 

 below. Water, however, is slowly given off, and after standing some days the salt 

 passes into a monohydrate analogous to the formate. 



When ignited, the acetate leaves a grey residue of scandia containing carbon. By 

 ignition alone it is difficult to get it of a constant weight. The best way to analyse 

 the salt is to moisten the weighed acetate with a few drops of nitric acid and 

 cautiously to evaporate to dryness, heat, and ignite. In this way is obtained pure 

 white scandia. 



Analysis. 



(1) 7'795 grs. of acetate left 2'449 grs. of scandia, = 1'5859 grs. of scandium. 



(2) 7-133 grs. left 2'270 grs. of scandia, = 1-4097 grs. of scandium. 



(3) 19"035 gi's. left on ignition G'OOO grs. of scandia, = 3 - 8848 grs. of scandium. 



Theory. Experiment. 



(1). (-2). (3). 



Sc 44-100 20-49 20'35 20'00 20'41 



(CH 3 COO) 2 . . 



OH )>171-088 79-51 79-05 79'40 79'59 



2H 2 



215-188 100-00 100-00 lOO'OO lOO'OO 



After being exposed to dry air for several days, the dihydrate loses one molecule of 

 water of crystallisation, and becomes a monohydrate 



(CH 3 COO) 3 ScOH,H 2 0. 



