Boric acid is a white powder with antiseptic properties. It can be used as an insecticide, fungicide, or as an ingredient in eye drops and antiseptic solutions.
| IUPAC Name | Boric Acid |
| Molecular Formula | H₃BO₃ |
| CAS Number | 10043-35-3 |
| Synonyms | Boracic acid, Orthoboric acid, Trihydroxidoboron |
| InChI | InChI=1S/BH3O3/c2-1(3)4/h2-4H |
Please note that the InChI provided is a simplified version, and you may want to consult reliable chemical databases for more detailed and accurate information.
Boric Acid Properties
Boric Acid Formula
The formula of orthoboric acid is H₃BO₃. It consists of three hydrogen atoms, one boron atom, and three oxygen atoms. The formula represents the composition of orthoboric acid at the molecular level.
Boric Acid Molar Mass
The molar mass of orthoboric acid is approximately 61.83 grams per mole. It is determined by adding up the atomic masses of its constituent elements according to the molecular formula H₃BO₃.
Boric Acid Boiling Point
Orthoboric acid has a boiling point of approximately 300 degrees Celsius (572 degrees Fahrenheit). This temperature indicates the point at which orthoboric acid transitions from a liquid phase to a gaseous phase when heated.
Boric Acid Melting Point
The melting point of orthoboric acid is around 170 degrees Celsius (338 degrees Fahrenheit). This temperature indicates the point at which orthoboric acid transitions from a solid phase to a liquid phase when heated.
Boric Acid Density g/mL
The density of orthoboric acid is about 1.44 grams per milliliter. Density is a measure of how much mass is contained in a given volume. In the case of orthoboric acid, this value represents the compactness of the substance.
Boric Acid Molecular Weight
The molecular weight of orthoboric acid is approximately 61.83 grams per mole. It is calculated by summing up the atomic weights of the individual atoms in a single molecule of orthoboric acid.
Boric Acid Structure
Orthoboric acid has a unique structure consisting of boron atoms bonded to three hydroxyl (OH) groups. It forms a trigonal planar arrangement with the boron atom at the center and the hydroxyl groups extending outward.
Boric Acid Solubility
Orthoboric acid is moderately soluble in water. It dissolves readily in water, especially when the water is heated. The solubility of orthoboric acid in water is influenced by factors such as temperature and pH levels.
| Appearance | White crystalline powder |
| Specific Gravity | 1.435 g/cm³ |
| Color | Colorless |
| Odor | Odorless |
| Molar Mass | 61.83 g/mol |
| Density | 1.44 g/mL |
| Melting Point | 170 °C (338 °F) |
| Boiling Point | 300 °C (572 °F) |
| Flash Point | Not applicable |
| Water Solubility | 25 g/L at 20 °C |
| Solubility | Soluble in solvents such as alcohol, glycerol |
| Vapour Pressure | 0.001 mmHg at 25 °C |
| Vapour Density | Not applicable |
| pKa | 9.14 |
| pH | Approximately 5.1 (0.1 M solution) |
Please note that these values are approximate and can vary depending on the specific conditions and purity of the orthoboric acid sample.
Boric Acid Safety and Hazards
Orthoboric acid can pose certain safety hazards if mishandled or improperly used. It is important to take the necessary precautions. Avoid direct contact with skin, eyes, and clothing, as it may cause irritation. Ingesting large amounts can be toxic and lead to health issues. When working with orthoboric acid, ensure good ventilation to prevent inhalation of its dust or vapors. In case of accidental ingestion or exposure, seek medical attention immediately. Store orthoboric acid in a secure place, away from children and pets. Follow proper disposal procedures to minimize environmental impact. Adhering to safety guidelines promotes safe handling and minimizes potential risks associated with orthoboric acid.
| Hazard Symbols | Xn (Harmful) |
| Safety Description | Avoid contact with skin and eyes. Use with adequate ventilation. Seek medical attention in case of ingestion or exposure. Keep away from children and pets. Follow proper disposal procedures. |
| UN IDs | UN3077 |
| HS Code | 2810.00.90 |
| Hazard Class | 9 (Miscellaneous Dangerous Substances and Articles) |
| Packing Group | III (Minor Danger) |
| Toxicity | Moderately toxic if ingested in large amounts. May cause irritation upon contact. |
Boric Acid Synthesis Methods
There are several methods to synthesize orthoboric acid.
Borax Acidification Method: Borax, also known as sodium borate, is acidified to produce orthoboric acid. To obtain pure orthoboric acid, mix a solution of borax with a strong acid, such as hydrochloric acid (HCl) or sulfuric acid (H₂SO₄). The acid reacts with the borax, releasing orthoboric acid as a precipitate. Filter, wash, and dry the precipitate to obtain pure orthoboric acid.
In the Boron Oxide Hydrolysis Method, hydrolyze boron oxide (B₂O₃) by reacting it with water (H₂O) under controlled conditions, typically at elevated temperatures. The reaction between B₂O₃ and H₂O produces orthoboric acid as the main product. Concentrate, crystallize, and dry the resulting orthoboric acid solution to obtain solid orthoboric acid.
The industry widely uses both methods mentioned above to produce orthoboric acid. The choice of method depends on factors such as availability of starting materials, desired purity, and scale of production. It is important to note that these synthesis methods involve the use of appropriate safety measures and adherence to applicable regulations to ensure the safe handling and production of orthoboric acid.
Boric Acid Uses
Orthoboric acid finds numerous applications across various industries due to its versatile properties. Here are some common uses of orthoboric acid:
- Insecticide and Pest Control: Orthoboric acid effectively controls pests like ants, cockroaches, and termites by disrupting their digestive systems, ultimately eliminating them.
- Preservative for Wood: Orthoboric acid preserves wood by protecting it against fungal and insect attacks. People commonly treat timber for construction, furniture, and other wooden structures.
- Flame Retardant: Orthoboric acid enhances the flame retardant properties of materials such as textiles, upholstery, and insulation, reducing their flammability and preventing fire spread.
- Eye Drops and Contact Lens Solution: Manufacturers use orthoboric acid in the production of eye drops and contact lens solution to cleanse and lubricate the eyes, providing relief from dryness and irritation.
- pH Buffer: Due to its weak acidic nature, orthoboric acid acts as a pH buffer in various products. It helps maintain the desired pH levels in cosmetics, personal care products, and pharmaceutical formulations.
- Antiseptic and Medicinal Uses: Orthoboric acid possesses antiseptic properties, making it useful in treating minor wounds, skin infections, and certain eye conditions. Various pharmaceutical preparations also employ orthoboric acid in their production.
- Glass and Ceramic Industry: Orthoboric acid is an essential ingredient in the manufacture of heat-resistant glass, ceramics, and fiberglass. It helps improve the strength, durability, and heat resistance of these materials.
Utilizers of orthoboric acid include a wide range of applications, as evidenced by the examples mentioned above. Its diverse properties make it a valuable compound in various industries, from household products to industrial processes.
Questions:
Q: What happens when boric acid is added to water?
A: When orthoboric acid is added to water, it dissolves and forms a solution of orthoboric acid.
Q: Is boric acid a protic acid? Explain.
A: Yes, orthoboric acid is a protic acid because it can donate a proton (H+) in a chemical reaction.
Q: How to prepare boric acid?
A: Orthoboric acid can be prepared by acidification of borax (sodium borate) or by hydrolysis of boron oxide (B₂O₃).
Q: How to dissolve boric acid in water?
A: To dissolve orthoboric acid in water, simply add it to the water and stir until the orthoboric acid dissolves completely.
Q: Is borax the same as boric acid?
A: No, borax (sodium borate) is not the same as orthoboric acid (H₃BO₃), although both contain boron.
Q: What is boric acid?
A: Orthoboric acid is a white crystalline compound with antiseptic, insecticidal, and preservative properties, commonly used in various applications.
Q: Where to buy boric acid?
A: Orthoboric acid can be purchased from various sources including online retailers, pharmacies, and stores that sell chemicals or household products.
Q: Is boric acid safe for humans?
A: Orthoboric acid can be toxic if ingested in large amounts, but when used as directed and in appropriate quantities, it is generally considered safe for humans.
Q: Which substances are bases? Check all that apply: NaOH, KOH, H₃BO₃, NaCl, Ca(OH)₂, Fe₂O₃.
A: The bases among the given substances are NaOH, KOH, Ca(OH)₂.
Q: Which formula stands for boric acid? H₃B, H₃BO₃, HBr, H₃PO₄.
A: The formula that stands for orthoboric acid is H₃BO₃.
Q: What is the oxidation number of boron (B) in H₃BO₃?
A: The oxidation number of boron (B) in H₃BO₃ is +3.
Q: Is H₃BO₃ a strong acid?
A: No, H₃BO₃ (orthoboric acid) is a weak acid.
Q: Is H₃BO₃ a strong or weak electrolyte?
A: H₃BO₃ (orthoboric acid) is a weak electrolyte.