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Calcium hydroxide

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Identification
Molecular formula
Ca(OH)2
CAS number
1305-62-0
IUPAC name
calcium;dihydroxide
State
State

Solid at room temperature.

Melting point (Celsius)
580.00
Melting point (Kelvin)
853.00
Boiling point (Celsius)
580.00
Boiling point (Kelvin)
853.00
General information
Molecular weight
74.09g/mol
Molar mass
74.0930g/mol
Density
2.2110g/cm3
Appearence

Calcium hydroxide appears as a colorless crystal or white powder. It is a soft, white, alkaline powder that is obtained when calcium oxide (lime) is mixed, or "slaked" with water. It has low toxicity.

Comment on solubility

Solubility of Calcium Dihydroxide

Calcium hydroxide, with the chemical formula Ca(OH)2, has some notable solubility characteristics. Generally, it can be described as slightly soluble in water. Let's explore its solubility in a bit more detail:

  • Solubility Product Constant (Ksp): The Ksp of calcium hydroxide is relatively low, indicating that only a small amount of it will dissolve in water.
  • Temperature Dependency: Its solubility increases with temperature, which means that warmer water can dissolve more of the compound compared to colder water.
  • pH Levels: Calcium hydroxide is often used to create alkaline solutions, as it can significantly increase the pH of the water in which it dissolves.

Interestingly, the solubility of calcium hydroxide can also be influenced by other factors, such as:

  • Presence of Carbon Dioxide: When exposed to CO2, calcium hydroxide can react to form calcium carbonate (CaCO3), which is particularly insoluble.
  • Ion Exchange Reactions: In certain solutions, Ca(OH)2 may engage in ion exchange, affecting its overall solubility.

In conclusion, the solubility of calcium hydroxide is an important factor in its applications, particularly in fields such as construction, where it is utilized in cement and mortar. As with many compounds, the environmental conditions play a crucial role in determining how much of it can dissolve in a given situation.

Interesting facts

Interesting Facts about Calcium Dihydroxide

Calcium dihydroxide, commonly known as slaked lime or hydrated lime, is a noteworthy compound with a variety of applications across different fields. Here are some fascinating aspects of this chemical:

  • Historical Significance: Calcium dihydroxide has been used since ancient times. It was a key ingredient in the construction of Roman structures, showcasing its durability and stability.
  • Building Material: In the construction industry, it is often used to create mortar, plaster, and for soil stabilization due to its excellent binding properties.
  • Neutralizing Agent: It plays a significant role in environmental chemistry, particularly in neutralizing acidic soils and waste water, making it a vital compound in agricultural practices.
  • Dental Applications: Calcium dihydroxide is widely used in dentistry as a pulp capping agent due to its biocompatibility and ability to stimulate the formation of secondary dentin.
  • Food Industry: In the food industry, it serves as a food additive (designated as E526). It's used in the processing of certain vegetables, for example, in the nixtamalization process of maize.

Chemical Properties and Reactions

Calcium dihydroxide exhibits interesting chemical behaviors:

  • It is a strong base, reacting with acids to form soluble salts and water.
  • When heated, it decomposes into calcium oxide and water, illustrating its role in thermodynamic processes.

Safety Precautions

While calcium dihydroxide is generally considered safe, proper safety measures should always be taken during handling:

  • Use protective eyewear to avoid irritation.
  • Avoid inhalation of dust, as it can irritate respiratory pathways.

Overall, calcium dihydroxide is an essential compound that highlights the intersection of chemistry with construction, environmental science, and food processing. Its versatility and historical significance make it a compound that continues to play a crucial role in both industrial and practical applications.

Synonyms
calcium;dihydroxide
MFCD00010901
Calcium hydroxide, ACS, 95%
12177-68-3
Portlandite (Ca(OH)2)
Calcium hydroxide, CP
Hydrated Lime Nanopowder
Ca (O H)2
Calcium hydroxide (JP17/USP)
HY-B2217D
Calcium hydroxide, LR, >=95%
Calcium hydroxide, p.a., 95.0%
Calcium hydroxide, puriss., 95.0%
Calcium hydroxide, ACS reagent, >=95.0%
Calcium hydroxide, USP, 95.0-100.5%
CS-0021597
CS-1101541
Calcium hydroxide, SAJ first grade, >=95.0%
D01083
Calcium hydroxide, 99.995% trace metals basis
Calcium hydroxide, SAJ special grade, >=96.0%
Calcium hydroxide, puriss. p.a., Reag. Ph. Eur., >=96%
Calcium hydroxide, United States Pharmacopeia (USP) Reference Standard
Calcium hydroxide, Ultra pure, FCC, Powder, Low heavy metals (Al: <= 2 ppm, As: <= 1 ppm, Cd: <= 1 ppm, Pb: <= 1 ppm & Hg: <= 0.1 ppm)