Edition: BP 2025 (Ph. Eur. 11.6 update)
General Notices
Lime Water
DEFINITION
Calcium Hydroxide
Purified Water, freshly boiled and cooled
Extemporaneous preparation
The following directions apply.
Shake together thoroughly and repeatedly; allow to stand until clear. Siphon off the clear solution as required.
Content of calcium hydroxide, Ca(OH)2
Not less than 0.15% w/v.
CHARACTERISTICS
A colourless liquid. It absorbs carbon dioxide from the air, a film of calcium carbonate being formed on the surface of the liquid. It becomes turbid when boiled and clear again on cooling.
IDENTIFICATION
Yields the reactions characteristic of calcium salts, Appendix VI.
ASSAY
Titrate 25 mL with 0.1M hydrochloric acid VS using phenolphthalein solution R1 as indicator. Each mL of 0.1M hydrochloric acid VS is equivalent to 3.705 mg of Ca(OH)2.
STORAGE
Calcium Hydroxide Solution should be kept in a well-filled container.
