In this reaction, sulfuric acid (H 2 SO 4 ), which is the oxyacid, reacts with sodium hydroxide (NaOH), creating as products sodium sulfate (Na 2 SO 4 ) , which is oxisal, and water (H 2 O). The ionic molecule of sodium sulfate has the sodium cation (Na + ) and the sulfate anion (SO 4 -2 ). On the other hand, this compound is present in nature, in brine deposits.
Oxysalts are part of a large number of natural substances on the planet. They are in the sands of the beaches, in the sea water, in the coral reefs, in the underground deposits and in the mountain systems, mainly. Thanks to their abundance, they are constantly used in human activities to satisfy needs.
Properties of oxysalts
Oxysalts, due to their ionic molecules, are characterized by the following properties:
- They are solid
- They dissociate when combined with water
- In aqueous solution, they are capable of conducting electrical current
- They have a crystalline structure
- They are capable of forming hydrates
- Medium to high melting points
Oxysalts are generally in solid state . When found in underground deposits or in mines, they are obtained as rocks, which can be crushed and pulverized for later use. For example calcium carbonate CaCO 3 , obtained as limestone. Those that are present in sand, such as silicates, already exist as particles or dust.
These chemical compounds when they come into contact with water are soluble , and form an aqueous solution. There they dissociate, that is, they separate into their ions , leaving the metal cation and the anion or radical. In the case of sodium sulfate, for example, the charges are:
Na 2 SO 4 -> Na + + SO 4 -2
In this way, the cations and anions remain flitting in the aqueous medium in such a way that, if an electric current is circulated through the solution, this mixture will be able to conduct it . The human being benefits from this property in electrochemical cells, to maintain a constant flow of electrical energy in laboratory practices.
Oxysalts have a crystalline internal structure . Its particles are in a certain degree of order, compact, enough to form crystals, which are defined geometric shapes that appear to the eye. For example, copper sulfate forms deep blue crystals, which have a little transparency.
Oxysalts, when found in an environment with high humidity, tend to form hydrates , which are oxysalt molecules to which water molecules are added , by attraction. This encourages the most abundant crystal formation. To take advantage, the hydrates have to be heated, so that the added water evaporates and becomes oxisal.
A hydrate can be: Na 2 SO 4 * 2H 2 O, called sodium sulfate dihydrate.
Oxysalts, being generally granular solids, have medium to high melting points. These are below the melting points of metals, which range in the thousands of degrees centigrade. Those of oxysalts are in the hundreds of degrees. In a liquid state, pure oxysalts are capable of conducting a little electrical current.
The way to name the oxysalts obeys several very similar rules, which can be classified as:
- When the metal of the oxisal has a single valence
- When the metal of the oxisal has different valences
When the metal of the oxisal has a single valence
Take as an example the sodium (Na) which only handles the valence +1, in sodium nitrate NaNO 3 . Two rules can be followed:
Radical name + “of” + Metal name: Sodium nitrate
Name of Radical + Name of metal with “ico” ending: Sodium nitrate
When the metal of the oxisalt has different valences
Iron (Fe) is taken as an example, which handles the valences +2 and +3, in the iron sulfates FeSO 4 , Fe 2 (SO 4 ) 3 . Two rules can be followed:
Name of the Radical + “of” + Name of the metal + valence of the metal in Roman numeral: Iron sulfate (II) FeSO 4 , Iron sulfate (III) Fe 2 (SO 4 ) 3 .
Radical Name + Name of the metal with valence termination “bear”, “ico”: Ferrous sulfate FeSO 4 , Ferric sulfate Fe 2 (SO 4 ) 3 .
Uses of the main oxysalts
- Calcium carbonate CaCO 3 , known as limestone, is a raw material that is added to concrete and other construction materials.
- Sodium sulfate Na 2 SO 4 is extracted from the subsoil as a component of the brine, and added to detergents as a diluent.
- KNO 3 potassium nitrate is a key ingredient in gunpowder and many other explosives.
- Calcium sulfate CaSO 4 , better known as gypsum, is another compound that is added to concrete mixes and prepared with water to repair surfaces or walls.
- NaClO sodium hypochlorite is used in dilute aqueous solution, and it is the disinfectant used to clean bathrooms.
- NaClO sodium hypochlorite
- Potassium Hypochlorite KClO
- Sodium chlorate NaClO 3
- Potassium Chlorate KClO 3
- Ferrous chlorate Fe (ClO 3 ) 2
- Ferric chlorate Fe (ClO 3 ) 3
- Sodium nitrate NaNO 3
- Potassium nitrate KNO 3
- Sodium sulfate Na 2 SO 4
- Potassium sulfate K 2 SO 4
- Magnesium Sulfate MgSO 4
- Calcium Sulfate CaSO 4
- Sodium carbonate Na 2 CO 3
- Potassium carbonate K 2 CO 3
- Magnesium Carbonate MgCO 3
- Calcium Carbonate CaCO 3
- Sodium phosphate Na 3 PO 4
- Potassium phosphate K 3 PO 4
- Magnesium phosphate Mg 3 (PO 4 ) 2
- Calcium phosphate Ca 3 (PO 4 ) 2
- Ferrous sulfate FeSO 4
- Ferric sulfate Fe 2 (SO 4 ) 3
- Zinc sulfate ZnSO 4
- Zinc carbonate ZnCO 3
- Sodium sulphite Na 2 SO 3
- Potassium sulphite K 2 SO 3
- Magnesium sulfite MgSO 3
- Calcium sulfite CaSO 3
- NaHCO 3 sodium bicarbonate
- KHCO 3 potassium bicarbonate
- Magnesium Bicarbonate Mg (HCO 3 ) 2
- Calcium bicarbonate Ca (HCO 3 ) 2
- Cadmium Sulfate CdSO 4