Potassium Hydroxide
KOH
56.11
56.11Potassium hydroxide.
Potassium hydroxide
[1310-58-3].» Potassium Hydroxide contains not less than 85.0 percent of total alkali, calculated as KOH, including not more than 3.5 percent of K2CO3.
Caution—Exercise great care in handling Potassium Hydroxide, as it rapidly destroys tissues.
Packaging and storage—
Preserve in tight containers.
Identification—
A solution (1 in 25) responds to the tests for Potassium 
191
.
191.
Insoluble substances—
Dissolve 1 g in 20 mL of water: the solution is complete, clear, and colorless.
Heavy metals 231—
Dissolve 0.67 g in a mixture of 5 mL of water and 7 mL of 3 N hydrochloric acid. Heat to boiling, cool, and dilute with water to 25 mL: the limit is 0.003%.
231—
Dissolve 0.67 g in a mixture of 5 mL of water and 7 mL of 3 N hydrochloric acid. Heat to boiling, cool, and dilute with water to 25 mL: the limit is 0.003%.
Assay—
Dissolve about 1.5 g of Potassium Hydroxide, accurately weighed, in 40 mL of carbon dioxide-free water. Cool the solution to 15
, add phenolphthalein TS, and titrate with 1 N sulfuric acid VS. At the discharge of the pink color of the indicator, record the volume of acid solution required, then add methyl orange TS, and continue the titration to a persistent pink color. Each mL of 1 N sulfuric acid is equivalent to 56.11 mg of total alkali, calculated as KOH, and each mL of acid consumed in the titration with methyl orange is equivalent to 138.2 mg of K2CO3.
, add phenolphthalein TS, and titrate with 1 N sulfuric acid VS. At the discharge of the pink color of the indicator, record the volume of acid solution required, then add methyl orange TS, and continue the titration to a persistent pink color. Each mL of 1 N sulfuric acid is equivalent to 56.11 mg of total alkali, calculated as KOH, and each mL of acid consumed in the titration with methyl orange is equivalent to 138.2 mg of K2CO3.
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
Chromatographic Column—
| Topic/Question | Contact | Expert Committee |
| Monograph | Robert H. Lafaver, B.A.
Scientist 1-301-816-8335 |
(EM105) Excipient Monographs 1 |
USP32–NF27 Page 1322
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.