7619. Potassium Carbonate

Nomenclature

CAS number: 584-08-7
Carbonic acid potassium salt (1:2); salt of tartar; pearl ash; potash.
CK2O3; mol wt 138.21.
C 8.69%, K 56.58%, O 34.73%.
K2CO3.

Properties

Hygroscopic, odorless granules or granular powder. d 2.29; mp 891°. Sol in 1 part cold, 0.7 part boiling water. Practically insol in alcohol. Its aq soln is strongly alkaline. pH 11.6. Keep tightly closed. LD50 orally in rats: 1.87 g/kg, H. F. Smyth et al., Am. Ind. Hyg. Assoc. J. 30, 470 (1969).

Derivative

Sesquihydrate.

Nomenclature

CAS number: 6381-79-9
CK2O3.1 1/2 H2O; mol wt 147.21.
C 8.16%, K 53.12%, O 38.04%, H 0.68%.

Properties

Small granular crystals. When it contains the full amount of water (16.36%) it is not hygroscopic. Sol in less than 1 part water. Practically insol in alcohol. The aq soln is strongly alkaline.

Caution

Irritant, caustic.

Use

Manuf soap, glass, pottery, smalts and many potassium salts; in process engraving and lithography; tanning and finishing leather; liq shampoos. Base. Anhydrous form as drying agent for organic solvents. Sesquihydrate used in invert sugar test, in buffers. Pharmaceutic aid (alkalizer).