What is a base in chemistry
In chemistryBase refers to a substance that, when in an aqueous solution, releases hydroxyl ions, increasing its alkaline properties.
In chemistry, the base or alkalis is a substance that when dissolved in an aqueous medium releases hydroxyl ions (OH-) and has alkaline properties.
Initially, bases were known as alkalis, since it is a substance that increases the pH of a solution by releasing hydroxyls, therefore alkalinizing it. Its name derives from Arabic Al-Qalywhich translates as ‘ash’.
Substances that have a pH level greater than 7 to 14 (maximum level) are considered bases and will have greater alkalinity. On the contrary, substances with a pH between 6 and 0 are considered acids.
It was from the 19th century that it was possible to better understand what a base and an acid are from the studies carried out by the scientists Svante August Arrhenius (1887), Johannes N. Brønsted and Thomas M. Lowry (1923, acid-base theory ), and Gilbert N. Lewis (1923).
Base characteristics
Among the main characteristics of the bases the following can be mentioned:
Depending on the temperature, bases can be found in liquid, solid or gaseous substances. They can be classified as strong bases or weak bases according to their dissociation, that is, their ability to provide OH- ions. They have a bitter taste. There may be bases that retain their properties in pure or diluted substances. Bases vary according to their pH level. In aqueous solutions they can be conductors of electricity. To the touch they are soapy. They are corrosive in various metals. When combined with acids they form salt. When smelled they can generate irritations. They can be irritating to the skin because they dissolve fat.
Examples of bases
Soaps are products for daily use that are part of the chemical bases. Its use is part of personal care and hygiene.
Bases are widely used in various types of industry, generally as catalysts or reagents. Hence they are used in the food, medical, soap and solvent manufacturing, electric battery manufacturing, and chemical industries, among others. Some examples of bases are:
Caustic soda (NaOH). Sodium bicarbonate (NaHCO3, deodorant). Ammonia (NH3). Magnesium hydroxide (Mg(OH)2, laxative). Calcium hydroxide (CaOH, lime). Sodium hypochlorite (NaCIO, sodium chlorine). cleaning).Potassium hydroxide (KOH, soap).Calcium fluoride (CaF2, allows working with infrared or ultraviolet waves)
Types of bases
There are two types of bases:
strong base: It is the one that dissociates in water and provides the greatest number of ions. For example, sodium hydroxide.
weak base: provides OH- ions in a balanced way with the number of molecules in the medium.
Basic nomenclatures
The nomenclatures of the bases are formed from the name of the element that combines with the hydroxyl ion (OH), the valence number is taken and they are combined. For example: CuOH2: copper hydroxide, Zn(OH)2: zinc hydroxide.
See also: