Potassium fluoride (KF) is a chemical compound that consists of K+ and F- ions. It is used in various industrial applications such as in the production of aluminium and in dental products.
| IUPAC Name | Potassium fluoride |
| Molecular Formula | KF |
| CAS Number | 7789-23-3 |
| Synonyms | Potassium monofluoride, Potassium fluorure, Kaliumfluorid, UN 1812, EINECS 232-151-5 |
| InChI | InChI=1S/FH.K/h1H;/q;+1/p-1 |
Potassium Fluoride Properties
Potassium Fluoride Formula
The chemical formula for potassium fluoride is KF, indicating that one potassium ion and one fluoride ion combine to form a single formula unit of the compound. The formula of potassium fluoride is useful in determining the stoichiometry of chemical reactions involving the compound, as well as in identifying the elements present in a given sample.
Potassium Fluoride Molar Mass
KF has a molar mass of 58.10 g/mol. It is a compound that consists of K+ and F- ions, with one potassium ion and one fluoride ion per formula unit. The molar mass is the sum of the atomic masses of the elements in a compound, which in this case are 39.10 g/mol for potassium and 19.00 g/mol for fluorine. Knowing the molar mass of KF is useful in determining the amount of the compound present in a given sample, as well as in calculating stoichiometric relationships in chemical reactions.
Potassium Fluoride Boiling Point
KF has a high boiling point of 1,503°C (2,737°F). This is due to the strong ionic bond between the K+ and F- ions, which requires a large amount of energy to break apart and allow the compound to enter the gaseous phase. The boiling point of KF makes it useful in high-temperature applications, such as in the production of aluminum, where it is used as a flux to remove impurities from the metal.
Potassium Fluoride Melting Point
KF has a relatively low melting point of 858°C (1,576°F). This is also due to the ionic nature of the compound, as the strong attraction between the positive and negative ions is weakened by the increase in temperature, allowing the compound to enter the liquid phase. The low melting point of KF makes it useful in a variety of applications, such as in the manufacturing of glass and ceramics.
Potassium Fluoride Density g/mL
The density of KF is 2.48 g/mL at room temperature. This value is influenced by the compact, crystalline structure of the compound, as well as the relatively high mass of the K+ and F- ions. The density of KF is useful in determining the volume occupied by a given mass of the compound, as well as in predicting its behavior in various environments.
Potassium Fluoride Molecular Weight
The molecular weight of KF is 58.10 g/mol. This value is determined by adding the atomic weights of the K+ and F- ions in one formula unit of the compound. The molecular weight of KF is important in determining its physical and chemical properties, as well as in calculating stoichiometric relationships in chemical reactions.
Potassium Fluoride Structure
KF has a crystalline structure that consists of alternating K+ and F- ions. The ions are held together by strong ionic bonds, which result in a highly stable and rigid structure. The structure of KF is important in determining its physical and chemical properties, as well as in predicting its behavior in various applications.
| Appearance | White crystalline solid |
| Specific Gravity | 2.48 at 20°C |
| Color | Colorless |
| Odor | Odorless |
| Molar Mass | 58.10 g/mol |
| Density | 2.48 g/mL at 20°C |
| Melting Point | 858°C |
| Boiling Point | 1,503°C |
| Flash Point | Not applicable |
| Water Solubility | 92.5 g/100 mL at 25°C |
| Solubility | Soluble in alcohol, insoluble in ether |
| Vapor Pressure | 1 mmHg at 737°C |
| Vapor Density | Not applicable |
| pKa | 7.3 |
| pH | 7 (neutral) |
Potassium Fluoride Safety and Hazards
KF can be hazardous if not handled properly. It is highly corrosive and can cause severe burns to the skin, eyes, and respiratory system upon contact. Inhalation of KF dust or vapors can irritate the respiratory system and lead to coughing and shortness of breath. Long-term exposure to KF can cause chronic lung damage and skeletal fluorosis. It is important to use protective equipment, such as gloves and goggles, when handling KF, and to avoid inhalation of its dust or vapors. In case of exposure, immediate medical attention should be sought.
| Hazard Symbols | Skull and crossbones, Corrosive |
| Safety Description | Keep locked up and out of the reach of children. Do not breathe dust. Wear suitable protective clothing, gloves and eye/face protection. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. In case of accident or if you feel unwell, seek medical advice immediately (show label where possible). |
| UN IDs | UN1812 |
| HS Code | 2826.12.00 |
| Hazard Class | 6.1 |
| Packing Group | II |
| Toxicity | Highly toxic; LD50 oral (rat) 52 mg/kg |
Potassium Fluoride Synthesis Methods
Several methods can synthesize KF. One common method is by reacting hydrofluoric acid (HF) with potassium hydroxide (KOH). The reaction produces KF and water, as follows:
HF + KOH → KF + H2O
Another method is the reaction between potassium carbonate (K2CO3) and hydrofluoric acid. The reaction produces KF, water, and carbon dioxide, as follows:
2HF + K2CO3 → 2KF + CO2 + H2O
At high temperatures, the reaction between hydrogen fluoride gas (HF) and potassium chloride (KCl) yields KF and hydrogen chloride gas (HCl).
KCl + HF → KF + HCl
The above methods require caution as hydrofluoric acid or hydrogen fluoride are highly corrosive and toxic.
Potassium Fluoride Uses
Potassium fluoride has several uses in different industries. Here are some of its uses:
- As a flux in metallurgy: Used as a flux in the production of aluminum and other metals. It helps remove impurities from the metal and improve its quality.
- In the production of other chemicals: Used in the production of several other chemicals, such as cryolite and aluminum fluoride.
- In the production of glass: Added to glass to lower its melting point and improve its durability and optical properties.
- In the production of pesticides: Used in the production of certain pesticides as a stabilizer and catalyst.
- In the production of toothpaste: Added to toothpaste as a fluoride supplement to prevent tooth decay.
- In nuclear reactors: Used in nuclear reactors as a coolant and to prevent the corrosion of the reactor’s components.
- In analytical chemistry: Used in analytical chemistry to determine the concentration of certain elements in a sample.
Questions:
Q: What is KF in chemistry?
A: KF is the chemical formula for potassium fluoride. It is an inorganic compound made up of one potassium ion and one fluoride ion.
Q: Is KF an acid or base?
A: KF is a salt that is neither an acid nor a base. However, it can undergo hydrolysis in water to produce a basic solution.
Q: Does potassium fluoride conduct electricity?
A: KF is an ionic compound that can conduct electricity when it is dissolved in water or melted. This is because the ions are able to move freely and carry an electric charge.
Q: What is the formula for potassium fluoride?
A: The formula for potassium fluoride is KF. The compound is made up of one K+ and one F- ion.