Base (chemistry) in the context of "Fen"

In chemistry, a salt or ionic compound is a chemical compound consisting of an assembly of positively charged ions (cations) and negatively charged ions (anions), which results in a compound with no net electric charge. The constituent ions are held together by electrostatic forces termed ionic bonds.

The component ions in a salt can be either inorganic, such as chloride (Cl), or organic, such as acetate (CH
₃COO
). Each ion can be either monatomic, such as sodium (Na) and chloride (Cl) in sodium chloride, or polyatomic, such as ammonium (NH
₄) and carbonate (CO
₃) ions in ammonium carbonate. Salts containing basic ions hydroxide (OH) or oxide (O) are classified as bases, such as sodium hydroxide and potassium oxide.

Lead (/lɛd/ ) is a chemical element with the symbol Pb (from the Latin plumbum) and atomic number 82. It is a heavy metal, denser than most common materials. Lead is soft, malleable, and has a relatively low melting point. When freshly cut, it appears shiny gray with a bluish tint, but tarnishes to dull gray on exposure to air. Lead has the highest atomic number of any stable element, and three of its isotopes are endpoints of major nuclear decay chains of heavier elements.

Lead is a relatively unreactive post-transition metal. Its weak metallic character is shown by its amphoteric behavior: lead and lead oxides react with both acids and bases, and it tends to form covalent bonds. Lead compounds usually occur in the +2 oxidation state rather than the +4 state common in lighter members of the carbon group, with exceptions mostly limited to organolead compounds. Like the lighter members of the group, lead can bond with itself, forming chains and polyhedral structures.

Soap is a salt of a fatty acid (sometimes other carboxylic acids) used for cleaning and lubricating products as well as other applications. In a domestic setting, soaps, specifically "toilet soaps", are surfactants usually used for washing, bathing, and other types of housekeeping. In industrial settings, soaps are used as thickeners, components of some lubricants, emulsifiers, and catalysts.

Soaps are often produced by mixing fats and oils with a base. Humans have used soap for millennia; evidence exists for the production of soap-like materials in ancient Babylon around 2800 BC.

Hydroxide is a diatomic anion with chemical formula OH. It consists of an oxygen and hydrogen atom held together by a single covalent bond, and carries a negative electric charge. It is an important but usually minor constituent of water. It functions as a base, a ligand, a nucleophile, and a catalyst. The hydroxide ion forms salts, some of which dissociate in aqueous solution, liberating solvated hydroxide ions. Sodium hydroxide is a multi-million-ton per annum commodity chemical.The corresponding electrically neutral compound HO is the hydroxyl radical. The corresponding covalently bound group −OH of atoms is the hydroxy group.Both the hydroxide ion and hydroxy group are nucleophiles and can act as catalysts in organic chemistry.

Many inorganic substances which bear the word hydroxide in their names are not ionic compounds of the hydroxide ion, but covalent compounds which contain hydroxy groups.

A hemicellulose (also known as polyose) is one of a number of heteropolymers (matrix polysaccharides), such as arabinoxylans, present along with cellulose in almost all terrestrial plant cell walls. Cellulose is crystalline, strong, and resistant to hydrolysis. Hemicelluloses are branched, shorter in length than cellulose, and also show a propensity to crystallize. They can be hydrolyzed by dilute acid or base as well as a myriad of hemicellulase enzymes.

In chemistry, pH (/piːˈheɪtʃ/ or /piːˈeɪtʃ/; pee-HAYCH or pee-AYCH) is a logarithmic scale used to specify the acidity or basicity of aqueous solutions. Acidic solutions (solutions with higher concentrations of hydrogen (H) cations) are measured to have lower pH values than basic or alkaline solutions. While the origin of the symbol 'pH' can be traced back to its original inventor, and the 'H' refers clearly to hydrogen, the exact original meaning of the letter 'p' in pH is still disputed; it has since acquired a more general technical meaning that is used in numerous other contexts.

The pH scale is logarithmic and inversely indicates the activity of hydrogen cations in the solution

A mordant or dye fixative is a substance used to set (i.e., bind) dyes on fabrics. It does this by forming a coordination complex with the dye, which then attaches to the fabric (or tissue). It may be used for dyeing fabrics or for intensifying stains in cell or tissue preparations. Although mordants are still used, especially by small batch dyers, they have been largely displaced in industry by substantive dyes.

The term mordant comes from the Latin mordere, "to bite". In the past, it was thought that a mordant helped the dye "bite" onto the fiber so that it would hold fast during washing. A mordant is often a polyvalent metal ion, and one example is chromium (III). The resulting coordination complex of dye and ion is colloidal and can be either acidic or alkaline.

In chemistry, an alkali (/ˈælkəlaɪ/ ; from the Arabic word al-qāly, القالِي) is a basic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The adjective alkaline, and less often, alkalescent, is commonly used in English as a synonym for basic, especially for bases soluble in water. This broad use of the term is likely to have come about because alkalis were the first bases known to obey the Arrhenius definition of a base, and they are still among the most common bases.

A soda lake or alkaline lake is a lake on the strongly basic side of neutrality, typically with a pH value between 9 and 12. They are characterized by high concentrations of carbonate salts, typically sodium carbonate (and related salt complexes), giving rise to their alkalinity. In addition, many soda lakes also contain high concentrations of sodium chloride and other dissolved salts, making them saline or hypersaline lakes as well. High pH and salinity often coincide, because of how soda lakes develop. The resulting hypersaline and highly alkaline soda lakes are considered some of the most extreme aquatic environments on Earth.

In spite of their apparent inhospitability, soda lakes are often highly productive ecosystems, compared to their (pH-neutral) freshwater counterparts. Gross primary production (photosynthesis) rates above 10 g C m day (grams of carbon per square meter per day), over 16 times the global average for lakes and streams (0.6 g C m day), have been measured. This makes them the most productive aquatic environments on Earth. An important reason for the high productivity is the virtually unlimited availability of dissolved carbon dioxide.