Calcium sulfite (CaSO3) is a compound that contains Ca2+ and SO32- ions. It is often used as a food preservative, antioxidant, and water purifier due to its ability to remove impurities and prevent spoilage.
| IUPAC Name | Calcium sulfite |
| Molecular Formula | CaSO3 |
| CAS Number | 10257-55-3 |
| Synonyms | Calcium sulphite; Sulfurous acid, calcium salt; Calcium sulfurous acid; Calcium sulphurous acid; E226 |
| InChI | InChI=1S/Ca.H2O3S/c;1-4(2)3/h;(H2,1,2,3)/q+2;/p-2 |
Calcium Sulfite Properties
Calcium Sulfite Formula
The chemical formula for calcium sulfite is CaSO3. This compound is composed of one Ca2+ ion and one SO32- ion. Calcium sulfite can be prepared by reacting calcium hydroxide with sulfurous acid. It is commonly used in the food industry as a preservative and antioxidant, and also as a water purifier.
Calcium Sulfite Molar Mass
The molar mass of CaSO3 is 120.14 g/mol. This can be calculated by adding the atomic masses of calcium (40.08 g/mol), sulfur (32.06 g/mol), and three oxygen atoms (16.00 g/mol each).
Calcium Sulfite Boiling Point
CaSO3 does not have a well-defined boiling point, as it decomposes before reaching its boiling point. However, it can be heated to a temperature of around 450°C before decomposition occurs. This is due to the fact that CaSO3 is an unstable compound, and tends to break down into calcium sulfate and sulfur dioxide when heated.
Calcium Sulfite Melting Point
The melting point of CaSO3 is approximately 1,520°C. This is the temperature at which the solid compound changes into a liquid state. CaSO3 has a crystalline structure and melts at a high temperature due to the strong ionic bonds between the calcium and sulfite ions.
Calcium Sulfite Density g/mL
The density of CaSO3 is approximately 2.71 g/mL. This means that one milliliter of CaSO3 has a mass of 2.71 grams. The high density of CaSO3 is due to the presence of the calcium ion, which has a high atomic mass.
Calcium Sulfite Molecular Weight
The molecular weight of CaSO3 is 120.14 g/mol. This can be calculated by adding the atomic weights of calcium, sulfur, and three oxygen atoms in the compound. The molecular weight of CaSO3 is important in determining its physical and chemical properties.
Calcium Sulfite Structure
The structure of CaSO3 consists of one Ca2+ ion and one SO32- ion. The calcium ion is surrounded by six oxygen atoms, while the sulfite ion has two oxygen atoms and one sulfur atom. The Ca2+ ion and SO32- ion is held together by ionic bonds, which are strong electrostatic forces of attraction between oppositely charged ions.
Calcium Sulfite Solubility
CaSO3 is sparingly soluble in water, with a solubility of approximately 0.17 g/100 mL at room temperature. This means that only a small amount of CaSO3 can dissolve in water, and the remaining solid particles will remain suspended in the water. The solubility of CaSO3 is affected by factors such as temperature, pH, and the presence of other ions.
| Appearance | White powder or crystalline solid |
| Specific Gravity | 2.71 |
| Color | White |
| Odor | Odorless |
| Molar Mass | 120.14 g/mol |
| Density | 2.71 g/mL |
| Melting Point | 1,520°C |
| Boiling Point | Decomposes before reaching boiling point |
| Flash Point | Not applicable |
| Water Solubility | Sparingly soluble, approx. 0.17 g/100 mL at room temp. |
| Solubility | Insoluble in alcohol and ether |
| Vapor Pressure | Not applicable |
| Vapor Density | Not applicable |
| pKa | 1.91 |
| pH | Slightly basic (pH 8-9 when dissolved in water) |
Calcium Sulfite Safety and Hazards
CaSO3 is generally considered safe for use in food and water treatment applications. However, like any chemical, it can pose certain hazards if not handled properly. CaSO3 is a skin and eye irritant and can cause respiratory irritation if inhaled. Ingestion of large quantities of CaSO3 can cause nausea, vomiting, and diarrhea. When handling CaSO3, one should take appropriate safety measures, such as wearing protective gloves and goggles. One should seek immediate medical attention if they come into contact with CaSO3 on their skin, eyes, or if they ingest it. It is also important to follow the proper storage and disposal procedures for CaSO3 to minimize potential hazards.
| Hazard Symbols | None assigned |
| Safety Description | Avoid contact with eyes, skin, and clothing. Wear protective gloves and goggles when handling. In case of contact, flush affected areas with water. In case of ingestion, seek immediate medical attention. |
| UN IDs | Not applicable |
| HS Code | 283210 |
| Hazard Class | Not classified as hazardous |
| Packing Group | Not applicable |
| Toxicity | Calcium sulfite is considered non-toxic in low concentrations, but can cause gastrointestinal irritation and other health effects in high doses. |
Calcium Sulfite Synthesis Methods
Reacting sulfurous acid with calcium hydroxide can synthesize CaSO3. The reaction produces CaSO3 and water as byproducts.
Another method involves reacting calcium carbonate with sulfurous acid, which produces CaSO3, water, and carbon dioxide. Typically, chemists carry out the reaction in a water solution at room temperature or slightly above.
In another method, reacting calcium oxide with sulfur dioxide, and then adding water to the resulting product produces CaSO3.
In industrial settings, the absorption of sulfur dioxide into a slurry of calcium hydroxide commonly produces CaSO3. This process produces a mixture of CaSO3 and calcium sulfate, which can be separated by filtration or other methods. One can use the resulting CaSO3 in a variety of applications, including water treatment and as a food preservative.
Overall, there are several methods for synthesizing CaSO3, each with its own advantages and limitations depending on the specific application and desired purity of the final product.
Calcium Sulfite Uses
CaSO3 has a variety of uses across different industries due to its unique properties. Some common uses of CaSO3 include:
- Water treatment: Often used as a water treatment agent to remove impurities and disinfect water. It can effectively remove chlorine, heavy metals, and other contaminants from water.
- Food preservation: Used as a food preservative to prevent spoilage and extend the shelf life of food products. Commonly used in the production of canned and bottled foods, as well as in wine and beer making.
- Chemical industry: Used in the chemical industry as a reducing agent and in the production of sulfuric acid.
- Construction: Used as a component of construction materials such as drywall and cement.
- Agricultural industry: Used in agriculture to treat soil and prevent plant diseases.
- Medical applications: Also used in medical applications as an antioxidant and as a treatment for some medical conditions.
Questions:
Q: What is the formula for calcium sulfite?
A: The formula for calcium sulfite is CaSO3.
Q: What is the state of calcium sulfite?
A: CaSO3 is a solid at room temperature.
Q: How many grams of calcium are present in 3.36 grams of CaSO3?
A: There are approximately 1.14 grams of calcium present in 3.36 grams of CaSO3.
Q: What happens when you add calcium carbonate to hydrochloric acid and sodium sulfite?
A: When calcium carbonate is added to hydrochloric acid and sodium sulfite, a reaction occurs that produces CaSO3, water, carbon dioxide, and sodium chloride.
Q: Does calcium sulfite dissolve in water?
A: Yes, CaSO3 is slightly soluble in water.
Q: Is calcium sulfite found in city water?
A: CaSO3 is not commonly found in city water, but it can be used in water treatment processes to remove impurities.
Q: Can CaSO3 be removed from drinking water?
A: Yes, CaSO3 can be removed from drinking water through various methods such as filtration, reverse osmosis, or chemical treatment.
Q: What do CaSO3 and HCl produce?
A: When CaSO3 is added to hydrochloric acid, a reaction occurs that produces calcium chloride, sulfur dioxide gas, and water.