calcium hydroxide

Also found in: Dictionary, Thesaurus, Medical, Acronyms, Wikipedia.
Related to calcium hydroxide: hydrobromic acid

calcium hydroxide

calcium hydroxide, Ca(OH)2, colorless crystal or white powder. It is prepared by reacting calcium oxide (lime) with water, a process called slaking, and is also known as hydrated lime or slaked lime. When heated above 580℃ it dehydrates, forming the oxide. Like the oxide, it has many uses, e.g., in liming soil, in sugar refining, and in preparing other compounds. It is a strong base and is widely used as an inexpensive alkali, often as a suspension in water (milk of lime); it is used in leather tanning to remove hair from hides. It is used in whitewash, mortar, and plaster. It is only slightly soluble in water, about 0.2 grams per 100 cubic centimeters, so its solutions are weakly basic. Limewater is a clear, saturated water solution of calcium hydroxide. It is used in medicine to treat acid burns and as an antacid. Because calcium hydroxide readily reacts with carbon dioxide, CO2, to form calcium carbonate, a mixture of gases can be tested for the presence of CO2 by shaking it with limewater in a clear container; if CO2 is present, a cloudy calcium carbonate precipitate will form.
The Columbia Electronic Encyclopedia™ Copyright © 2022, Columbia University Press. Licensed from Columbia University Press. All rights reserved.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Calcium Hydroxide


slaked lime, Ca(OH)2, a strong base; colorless crystals. Density, 2.24 g per cm3.

Commercial calcium hydroxide is a fluffy white powder. It dehydrates to CaO when heated. Calcium hydroxide is only slightly soluble in water: 0.165 g per 100 g H2O at 20°C and 0.077 g at 100°C. Its solubility increases sharply in the presence of salts. An aqueous solution of calcium hydroxide is known as lime water; a suspension is known as milk of lime. Calcium hydroxide readily absorbs atmospheric carbon dioxide: Ca(OH)2 + CO2 = CaCO3 + H2O. The compound serves as an inexpensive alkali. It is also used in construction.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

calcium hydroxide

[′kal·sē·əm hī′dräk‚sīd]
(inorganic chemistry)
Ca(OH)2 White crystals, slightly soluble in water; used in cement, mortar, and manufacture of calcium salts. Also known as hydrated lime.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

hydrated lime

1. Same as dry hydrate.
2. Quick lime mixed with water, on the job, to form a lime putty; slaked lime.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.

calcium hydroxide

a white crystalline slightly soluble alkali with many uses, esp in cement, water softening, and the neutralization of acid soils. Formula: Ca(OH)2
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
References in periodicals archive ?
It has been shown that in an aerobic atmosphere MTA can generate reactive oxygen species which, as reported above, have an antimicrobial activity similar to that obtained with calcium hydroxide. However, under anaerobic conditions, a decrease in the generation of radicals was observed [51].
At each time step, the calcium hydroxide contents, capillary water contents, chemically bound water contents, gel-space ratio, and compressive strength of hardening nanosilica blended concrete are determined using the cement hydration degree and the nanosilica reaction degree.
Comparing with mixtures made with calcium hydroxide was saved some relation, although the same concentration is much greater the weight of calcium carbonate than the lime.
Dentin cylinders or bars milled from bovine or human teeth respectively, were treated with calcium hydroxide and subjected to compressive or shear forces.
Endodontic management and the use of calcium hydroxide in traumatized permanent teeth.
After the temporary restoration and calcium hydroxide dressing were removed, the canal was chemically cleaned again with sequential passive ultrasonic irrigation using 2.5% NaOCl, followed by 10 mL 17% EDTA for 1 min, 0.9% normal saline, and 2% chlorhexidine solution.
Comparative evaluation of mixture of calcium hydroxide and chlorehexidine with triple antibiotic paste and combination of calcium hydroxide, chlorhexidine and lycopene on incidence of interappointment flare-up: An in vivo study.
Calcium hydroxide has been used famously in the past for induction of apical barrier, having success rates ranging from 79%-96%.6 However, being a long history of use in apical closure procedures, there are many drawbacks associated with the use of calcium hydroxide for apexification procedure.
12 compared the direct pulp capping of four groups: MTA, BiodentineA calcium hydroxide
The canal was accessed, and pulp extirpation performed before the placement of intracanal nonsetting calcium hydroxide by the general dental practitioner (GDP).