In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group attached to an R-group. The general formula of a carboxylic acid is R−COOH or R−CO2H, with R referring to the alkyl, alkenyl, aryl, or other group. Carboxylic acids occur widely. Important examples include the amino acids and fatty acids. Deprotonation of a carboxylic acid gives a carboxylate anion.
In chemistry, an ester is a compound derived from an acid in which the hydrogen atom (H) of at least one acidic hydroxyl group of that acid is replaced by an organyl group. Analogues derived from oxygen replaced by other chalcogens belong to the ester category as well. According to some authors, organyl derivatives of acidic hydrogen of other acids are esters as well, but not according to the IUPAC.
Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations Na+ and hydroxide anions OH−.
Transesterification is the process of exchanging the organic functional group R″ of an ester with the organic group R' of an alcohol. These reactions are often catalyzed by the addition of an acid or base catalyst. The reaction can also be accomplished with the help of other enzymes, particularly lipases.
Potassium hydroxide is an inorganic compound with the formula KOH, and is commonly called caustic potash.
In organic chemistry, methoxides are organic salts with a CH3O− anion. They are the simplest alkoxides. Sodium methoxide and potassium methoxide have widespread use, though other metal-cation variants such as lithium methoxide, rubidium methoxide, and caesium methoxide exist as well.
Biodiesel production is the process of producing the biofuel, biodiesel, through the chemical reactions of transesterification and esterification. This involves vegetable or animal fats and oils being reacted with short-chain alcohols. The alcohols used should be of low molecular weight. Ethanol is the most used because of its low cost, however, greater conversions into biodiesel can be reached using methanol. Although the transesterification reaction can be catalyzed by either acids or bases, the base-catalyzed reaction is more common. This path has lower reaction times and catalyst cost than those acid catalysis. However, alkaline catalysis has the disadvantage of high sensitivity to both water and free fatty acids present in the oils.August 10th is international biodiesel day
Methyl formate, also called methyl methanoate, is the methyl ester of formic acid. The simplest example of an ester, it is a colorless liquid with an ethereal odour, high vapor pressure, and low surface tension. It is a precursor to many other compounds of commercial interest.
Methyl acetate, also known as MeOAc, acetic acid methyl ester or methyl ethanoate, is a carboxylate ester with the formula CH3COOCH3. It is a flammable liquid with a characteristically pleasant smell reminiscent of some glues and nail polish removers. Methyl acetate is occasionally used as a solvent, being weakly polar and lipophilic, but its close relative ethyl acetate is a more common solvent being less toxic and less soluble in water. Methyl acetate has a solubility of 25% in water at room temperature. At elevated temperature its solubility in water is much higher. Methyl acetate is not stable in the presence of strong aqueous bases or aqueous acids. Methyl acetate is not considered a VOC in the USA.
Fatty acid methyl esters (FAME) are a type of fatty acid ester that are derived by transesterification of fats with methanol. The molecules in biodiesel are primarily FAME, usually obtained from vegetable oils by transesterification. They are used to produce detergents and biodiesel. FAME are typically produced by an alkali-catalyzed reaction between fats and methanol in the presence of base such as sodium hydroxide, sodium methoxide or potassium hydroxide. One of the reasons for FAME use in biodiesel instead of free fatty acids is to nullify any corrosion that free fatty acids would cause to the metals of engines, production facilities and so forth. Free fatty acids are only mildly acidic, but in time can cause cumulative corrosion unlike their esters. As an improved quality, FAMEs also usually have about 12-15 units higher cetane number than their unesterified counterparts.
In chemistry, acid value is a number used to quantify the acidity of a given chemical substance. It is the quantity of base, expressed as milligrams of KOH required to neutralize the acidic constituents in 1 gram of a sample.
Xanthate usually refers to a salt of xanthic acid. The formula of the salt of xanthic acid is [R−O−CS2]−M+ ,. Xanthate also refers to the anion [R−O−CS2]−. Xanthate also may refer to an ester of xanthic acid. The formula of xanthic acid is R−O−C(=S)−S−H, while the formula of the esters of xanthic acid is R−O−C(=S)−S−R', where R and R' are organyl groups. The salts of xanthates are also called O-organyl dithioates. The esters of xanthic acid are also called O,S-diorganyl esters of dithiocarbonic acid. The name xanthate is derived from Ancient Greek ξανθός xanthos, meaning “yellowish, golden”, and indeed most xanthate salts are yellow. They were discovered and named in 1823 by Danish chemist William Christopher Zeise. These organosulfur compounds are important in two areas: the production of cellophane and related polymers from cellulose and for extraction of certain sulphide bearing ores. They are also versatile intermediates in organic synthesis.
The Tishchenko reaction is an organic chemical reaction that involves disproportionation of an aldehyde in the presence of an alkoxide. The reaction is named after Russian organic chemist Vyacheslav Tishchenko, who discovered that aluminium alkoxides are effective catalysts for the reaction.
Sodium formate, HCOONa, is the sodium salt of formic acid, HCOOH. It usually appears as a white deliquescent powder.
Sodium methoxide is the simplest sodium alkoxide. With the formula CH3ONa, it is a white solid, which is formed by the deprotonation of methanol. It is a widely used reagent in industry and the laboratory. It is also a dangerously caustic base.
Dimethyl oxalate is an organic compound with the formula (CO2CH3)2. It is the dimethyl ester of oxalic acid. Dimethyl oxalate is a colorless or white solid that is soluble in water.
Fatty acid esters (FAEs) are a type of ester that result from the combination of a fatty acid with an alcohol. When the alcohol component is glycerol, the fatty acid esters produced can be monoglycerides, diglycerides, or triglycerides. Dietary fats are chemically triglycerides.
Saltwater soap, also called sailors' soap, is a potassium-based soap for use with seawater. Inexpensive common commercial soap will not lather or dissolve in seawater due to high levels of sodium chloride in the water. Similarly, common soap does not work as well as potassium-based soap in hard water where calcium replaces the sodium, making residual insoluble "scum" due to the insolubility of the soap residue. To be an effective cleaning agent, soap must be able to dissolve in water.
11-Aminoundecanoic acid is an organic compound with the formula H2N(CH2)10CO2H. This white solid is classified as an amine and a fatty acid. 11-Aminoundecanoic acid is a precursor to Nylon-11.
In chemistry, an alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom. They are written as RO−, where R is the organic substituent. Alkoxides are strong bases and, when R is not bulky, good nucleophiles and good ligands. Alkoxides, although generally not stable in protic solvents such as water, occur widely as intermediates in various reactions, including the Williamson ether synthesis. Transition metal alkoxides are widely used for coatings and as catalysts.
