§ 25. HE AGENTS. • 10 



h. PotaSSic blSUlphatC— KHSO^. (Bisulphate of po- 

 tasga. K0,H0,S03.) 



c. PotaSSic Chromate. — ^K^CrO^. (Chromate of po- 

 tassa. KOjCrOg.) — This should give no turbidity with 

 argentic nitrate, after acidification with nitric acid. Make 

 a cold saturated solution. 



d. PotasSic chlorate. — KCIO^. (Chlorate of potassa. 

 K0,C10,.) 



e. Potassic dichromate. — K^Cr^O,. (Bichromate of 

 potassa. KO,2Cr03.) — This should be recrystallized. 

 Dissolve it in 12 parts of water. 



/. Potassic fcrricyanide.— K3Cy,re. K3Cfdy. (Fer- 

 ricyanide of potassium. KgCy^Fe^.) — This should give 

 no blue color wdth ferric chloride. 



g. Potassic ferrocyanide.— K^Cy^Fe. K.Cfy. (Fer- 

 rocyanide of potassium. K2Cy3Fe.) — Dissolve in 12 parts 

 of water. 



A. Potassic hydrate.— KHO. (Potassa KO,HO.)— 

 This should not be changed by ammonic sulphydrate, and 

 should effervesce but slightly if at all with hydrochloric acid; 

 the solution obtained with hydrochloric acid in excess, 

 when evaporated to dryness should give a residue that is 

 at least almost completely dissolved by water ; the same 

 solution should give, at the most, but a very slight reac- 

 tion for i^hosphoric acid with ammonic molybdate, and 

 should give but a slight flocculent precipitate with am- 

 monia in excess, after long standing in a warm place. 

 Pure potassa prepared from an alchoholic solution of the 

 hydrate should give none of these reactions. Dissolve in 

 10 parts of water. 



i, Potassic iodide. — KI. (Iodide of potassium.) — This 

 is sufficiently pure as obtained from the druggists. 



Jc, Potassic permanganate. — K^Mn^Og. (Perman- 

 ganate of potassa. KOjMn^O,.) 



