What do salts have in common?

Properties of salts

In a narrow sense, salt is understood to be sodium chloride (NaCl, table salt), but in a broad sense, salts are all compounds that are built up from anions and cations.

General properties of salts

Salts ...:

  • are soluble in dipoles (e.g. water).
  • are Not soluble in organic liquids (e.g. lactic acid).
  • have the same molecular structure.
  • crystallize.
  • have a high melting point.
  • are mostly colorless.
  • have barely perceptible, individual smells.
  • are usually solid at room temperature.

Properties of sodium chloride

Conductivity: Does not conduct in the crystalline state, but only in the dissolved or molten state.
Melting point: The melting point of sodium chloride is 801 ° C.
Boiling point: 1465 ° C
Physical state: solid
Ratio formula: NaCl
Flame color: orange
It has the typical salt taste and is both colorless and odorless. It is also very soluble in water.

  • Sodium chloride is often found in nature, but for the most part it is found in solution in seawater. The average salinity of the oceans is 3.5%. The highest salinity is 44.2% and can be found in Don Juan Lake.

Here is a picture of the ionic lattice of sodium chloride.



Melting point of salts

Salts have a very high melting point. In salts there are ions that have positive or negative charges. (Example: Sodium chloride consists of positive sodium ions and negative chlorine ions. Na+Cl-) Negative and positive ions attract each other, especially in the solid state.
Since all particles vibrate, ions also vibrate.

What happens when salts are melted?

When melting, the ions are separated from each other. The addition of energy increases the natural oscillation of the ions and as soon as the energy exceeds the melting point, the oscillation is so great that the association of ions "collapses". The ions move freely and the salt melts.

The melting point of salts is so high that the ions hold each other together due to the ion charges, which means that more energy is required to separate the association than with compounds without charges.

Sources: http://de.wikibooks.org/wiki/Anorganische_Chemie_f%C3%BCr_Sch%C3%BCler:_Ionen,_Salze,_F%C3%A4llungsreaktionen_und_Ionenbendung#Der_Schmelzpunkt_von_Salzen_ist_sehr_hoch.

Conductivity of salts

Sodium chloride is a salt that is solid at room temperature. In this aggregate state it cannot conduct because the ions cannot move freely. However, when salts are in the liquid or dissolved state, charged ions can move freely and move to plus and minus poles. There are two different types of ions: cations and anions. Cations "migrate" to the positive pole (cathode) and anions to the negative pole (anode).
As soon as the temperature rises or falls, the mobility of the ions and thus the conductivity also change. The higher the temperature, the better the salts.

Sources: http://www.aks.rub.de/getP/Daten/C008/doc/elf.pdf

Solubility of salt

Why does salt dissolve in water?

Salt is made up of crystals made up of positively charged ions and negatively charged ions. During the dissolution process, the water molecules accumulate around the ions and dissolve their bond. Water is a dipole, which means it has a negative pole and a positive pole. The ions are attracted in different directions, and so the crystal structure of salt "tears". In the sodium chloride NaCl example, which is explained in more detail, the sodium ions are positively charged and the chloride ions are negatively charged. In general, salt always dissolves in water.


  • Melting Sodium Chloride (NaCl)



  • Solubility of Salt in Water


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