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Sodium fluoride is an inorganic ionic compound, dissolving in water to give separated Na + and F − ions. Like sodium chloride , it crystallizes in a cubic motif where both Na + and F − occupy octahedral coordination sites ; [ 33 ] [ 34 ] its lattice spacing, approximately 462 pm , is smaller than that of sodium chloride (564 pm).
Typically the fluoride anion is surrounded by four or six cations, as is typical for other halides. Sodium fluoride and sodium chloride adopt the same structure. For compounds containing more than one fluoride per cation, the structures often deviate from those of the chlorides, as illustrated by the main fluoride mineral fluorite (CaF 2 ...
Sodium fluoride: yellow is fluorine, purple is sodium. They are isoelectronic, but fluorine is bigger because its nuclear charge is lower. The alkali metals form monofluorides. All are soluble and have the sodium chloride (rock salt) structure, [47] Because the fluoride anion is basic, many alkali metal fluorides form bifluorides with the ...
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
In the simplest case, the cation is a metal atom and the anion is a nonmetal atom, but these ions can be more complex, e.g. polyatomic ions like NH + 4 or SO 2− 4. In simpler words, an ionic bond results from the transfer of electrons from a metal to a non-metal to obtain a full valence shell for both atoms.
Ionic radius, r ion, is the radius of a monatomic ion in an ionic crystal structure. Although neither atoms nor ions have sharp boundaries, they are treated as if they were hard spheres with radii such that the sum of ionic radii of the cation and anion gives the distance between the ions in a crystal lattice.
This occurs during hydration of metal ions, so colorless anhydrous salts with an anion absorbing in the infrared can become colorful in solution. [81] Salts exist in many different colors, which arise either from their constituent anions, cations or solvates. For example: sodium chromate Na 2 CrO 4 is made yellow by the chromate ion CrO 2− 4.
Solubility of salts in organic solvents is a function of both the cation and the anion. The solubility of cations in organic solvents can be enhanced when the anion is lipophilic. Similarly, the solubility of anions in organic solvents is enhanced with lipophilic cations. The most common lipophilic cations are quaternary ammonium cations ...