Main Difference – Sodium Fluoride vs Calcium Fluoride
Fluorides are chemical compounds containing fluoride ions (F–). Sodium fluoride and calcium fluoride are two such compounds. Sodium fluoride (NaF) is composed of sodium cation and fluoride anion. It is a medication used to prevent tooth decay caused by the low fluoride uptake. It is also used to treat children in areas where fluoride content in drinking water is low. Calcium fluoride is composed of calcium cation and fluoride anion. It is present in the form of a naturally occurring mineral called fluorite. The main difference between sodium fluoride and calcium fluoride is that sodium fluoride contains one sodium cation in association with one fluoride anion whereas calcium fluoride contains one calcium cation in association with two fluoride anions.
Key Areas Covered
1. What is Sodium Fluoride
– Definition, Chemical Properties, Production, Uses
2. What is Calcium Fluoride
– Definition, Chemical Properties, Production, Uses
3. What is the Difference Between Sodium Fluoride and Calcium Fluoride
– Comparison of Key Differences
Key Terms: CaF2, Calciums, Calcium Fluoride, Fluoride, NaF, Sodium, Sodium Fluoride
What is Sodium Fluoride
Sodium fluoride is an inorganic salt composed of sodium cations and fluoride anions. The chemical formula of sodium fluoride is NaF. The molar mass of this compound is 41.99 g/mol. It is a white to greenish solid compound that is odorless.
The melting point of Sodium fluoride is 993 °C, and the boiling point is 1,704 °C. Sodium fluoride is an ionic compound. This compound exists in a cubic, crystalline structure that is similar to the structure of sodium chloride; NaCl.
Figure 1: Sodium Fluoride Ionic Structure
Sodium fluoride occurs in nature in the form of villiaumite, which is a rare mineral. However, it is made industrially for its applications. It is produced by the neutralization of hydrofluoric acid (HF) using a suitable base. This involves the reaction between HF and NaOH. HF is obtained as a byproduct of the production of phosphoric acid from fluorophosphates by wet process.
HF + NaOH → NaF + H2O
Sodium fluoride is composed of sodium cation and fluoride anion. It is used as a medication to prevent tooth decay caused by the low fluoride uptake. It is used also to treat children in areas where fluoride content in drinking water is low. NF also has many applications in chemistry for synthesis and extractive metallurgy. In addition, it is used in organic synthesis reactions, as a cleaning agent and as a poison for plant-feeding insects.
What is Calcium Fluoride
Calcium fluoride is an inorganic salt composed of calcium cation and fluoride anions. The chemical formula of calcium fluoride is CaF2, and the molar mass is 78.07g/mol. It appears as a white crystalline solid. However, the single crystals of Calcium fluoride are transparent.
Figure 2: Calcium Fluoride Powder
The melting point of calcium fluoride is 1,418 °C, and the boiling point is 2,533 °C. Calcium fluoride occurs naturally as fluorite mineral. It has a deep color due to the presence of different impurities. It is abundant but is mainly used for the production of HF acid. High purity Calcium fluoride is industrially produced by treating calcium carbonate (CaCO3) with hydrofluoric acid (HF).
CaCO3 + 2HF → CaF2 + CO2 + H2O
As an application, naturally occurring fluorite is used as a precursor for the production of HF acid. This production process involves calcium fluoride reaction with sulfuric acid, which yields calcium sulfate (CaSO4) solid and HF gas. Calcium fluoride is used for the production of optical components such as windows, lenses, etc.
Difference Between Sodium Fluoride and Calcium Fluoride
Definition
Sodium Fluoride: Sodium fluoride is an inorganic salt composed of a sodium cation and a fluoride anion.
Calcium Fluoride: Calcium fluoride is an inorganic salt composed of a calcium cation and fluoride anions.
Chemical Formula
Sodium Fluoride: The chemical formula of Sodium fluoride is NaF.
Calcium Fluoride: The chemical formula of calcium fluoride is CaF2.
Molar Mass
Sodium Fluoride: The molar mass of Sodium fluoride is 41.99 g/mol.
Calcium Fluoride: The molar mass of calcium fluoride is 78.07g/mol.
Melting Point and Boiling Point
Sodium Fluoride: The melting point of Sodium fluoride is 993 °C, and the boiling point is 1,704 °C.
Calcium Fluoride: The melting point of calcium fluoride is 1,418 °C, and the boiling point is 2,533 °C.
Occurrence
Sodium Fluoride: Sodium fluoride occurs in nature in the form of villiaumite, which is a rare mineral.
Calcium Fluoride: Calcium fluoride occurs naturally as fluorite mineral.
Uses
Sodium Fluoride: Sodium fluoride is mainly used as a medication for tooth decay.
Calcium Fluoride: Calcium fluoride is mainly used as a precursor to produce HF acid.
Production
Sodium Fluoride: Sodium fluoride is produced by the reaction between HF and NaOH.
Calcium Fluoride: Calcium fluoride is industrially produced by treating calcium carbonate (CaCO3) with hydrofluoric acid (HF).
Conclusion
Sodium fluoride and calcium fluoride are fluoride salts. The main difference between sodium fluoride and calcium fluoride is that sodium fluoride contains one sodium cation in association with one fluoride anion whereas calcium fluoride contains one calcium cation in association with two fluoride anions.
Reference:
1. “Sodium fluoride.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine, Available here.
2. “Calcium fluoride.” Wikipedia, Wikimedia Foundation, 20 Jan. 2018, Available here.
Image Courtesy:
1. “Sodium-fluoride-3D-ionic” By Benjah-bmm27 – Own work (Public Domain) via Commons Wikimedia
2. “Calcium fluoride” ( Public Domain) via Commons Wikimedia
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