The Bases have a soapy appearance. Arrhenius’ definition indicated that base is any substance that in aqueous solution is ionized to give rise to OH ions “. This explains the basic behavior of NaOH . And another clear example is potassium hydroxide, formula KOH :
- KOH → OH- + K + (in aqueous solution)
Summary
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- 1 Definitions of basis
- 2 Nomenclature of bases
- 3 Formation of the bases
- 4 Properties of the bases
- 5 Most Common Bases
- 6 Sources
Base definitions
The initial definition corresponds to that formulated in 1887 by Arrehnius. Brönsted and Lowry’s theory of acids and bases, formulated in 1923, says that a base is that substance capable of accepting a proton (H + ). This definition includes the previous one: in the previous example, the KOH when dissociating in solution gives OH – ions , which are the ones that act as a base when being able to accept a proton. This theory can also be applied in non-aqueous solvents. Lewis in 1923 further expanded the definition of acids and bases, although Lewis’s theory would not have an impact until years later. According to Lewis’s theory, a base is that substance that can give up an electron pair. OH ion –Like other ions or molecules such as NH 3 , H 2 O, etc., they have a pair of non-binding electrons, making them bases. All bases according to the theory of Arrehnius or Brönsted and Lowry are in turn Lewis bases.
- Examples of Arrehnius bases: NaOH, KOH, Al (OH) 3.
- Examples of Brönsted and Lowry bases: NH 3, S 2 – , HS – .
Base nomenclature
To create a base using various nomenclatures for them taken from the names of the elements and joining them with a hydroxyl ion (OH), taking the valence number of the element and combining them (changing their position) as shown in the table:
| Formula | Traditional | Stock | IUPAC |
| Cu (OH) | Cuprous hydroxide | Copper hydroxide (I) | Copper monohydroxide |
| Cu (OH) 2 | Cupric hydroxide2 | Copper (II) hydroxide | Copper dihydroxide |
When an item has more than two valences, it is not traditionally named. When using the lowest valence, the element ends in bear and when using the highest valence it ends in ico. In the IUPAC nomenclature, a prefix conformation will be given to the element according to its used valence (Mono, Di, Tri, Tetra, Penta, Hexa, etc.) together with the ending -hydroxy or -oxydrile which is the OH ion with charge −1.
Base formation
A base is formed when an oxide of a metal reacts with water:
- MgO + H 2O → Mg (OH) 2
the same is:
- Al 2O 3 + 3H 2 O → 2Al (OH) 3
Base properties
The bases…
- They change color to the indicators previously treated with acids.
- In solution, they have a bitter (bleach) flavor; they also destroy living tissues and conduct electrical current.
- They nullify (“neutralize”) the effect of acids.
- They generate precipitates (solid phase substances in a liquid) when they are put in contact with certain metal salts (for example, calcium and magnesium).
- Its aqueous solutions produce a soft (soapy) feeling to the touch.
- Its aqueous solutions change the color of many vegetable dyes; for example, they return the blue color to litmus reddened by acids.
- Many substances precipitate, which are soluble in acids.
- They lose all their characteristic properties when they react with an acid .
Both acids and bases are found in large quantities in products used in daily life, for industry and hygiene, as well as in fruits and other foods, while the excess or defect of their relative amounts in our body translates into problems of Health.
Most Common Bases
Some examples of bases are:
- Caustic soda (NaOH)
- The chlorine pool (sodium hypochlorite)
- Antacids in general
- Cleaning products
- Ammonia (NH 3)
- Milk of magnesia ( magnesium hydroxide ), (Mg (OH) 2)
- The sodium bicarbonate
- Soap and detergent (sodium hydroxide).
