Alcohols are widely used as solvents, fuels and
chemical raw materials. Generally, hydroxyl group compounds are polar, which
trends to promote solubility in water. But the carbon chain resist to solubility
in water. Short chain alcohols (methanol, ethanol, and propanol) in which the
hydroxyl group predominates are miscible in water. Butanol is moderately soluble
because of the balance between the two opposing solubility trends. Higher
alcohols are practically insoluble in water because of the hydrocarbon chain's
trend is stronger. Alcohols are "protic" solvents. Protic refers to a hydrogen
atom attached to an electronegative atom, oxygen. Polar protic solvents are
compounds that can be represented by the general formula ROH of which water
(H2O), methanol (CH3OH) and acetic acid (CH3COOH) are examples.
Water-soluble alcohols, low-molecular weight products,
are solvents for the manufacture of coatings, dyes and
inks, plastics, flavorings, personal-care products,
pharmaceuticals, and cleaners. The higher alcohols,
slightly soluble in water or insoluble, can provide
the proper balance of target properties when solvent-based
solvents are formulated for desired viscosity, flowing
and leveling, and curing rate and can be used as coupling
agents in waterborne coatings.
very weak acids as they lose H+ in the hydroxyl group. Alcohols undergoes
dehydration reaction which means the elimination of water molecule replaced by
a pi bond between two adjacent carbon atoms to form alkenes under heating in the
presence of strong acids like hydrocloric acid or phosphoric acid. Primary and
secondary alcohols can be oxidized to aldehydes and ketones respectively.
Carboxylic acids are obtained from oxidation of aldehydes. Oxidation in organic
chemistry can be considered to be the loss of hydrogen or gain of oxygen and
reduction to gain hydrogen or loss of oxygen. Tertiary alcohols do not react to
give oxidation products as they have no H attached to the alcohol carbon.
Alcohols undergoes important reactions called nucleophilic substitution in which
an electron donor replaces a leaving group, generally conjugate bases of strong
acids, as a covalent substitute of some atom. One of important reaction of
alcohol is condensation. Ethers are formed by the condensation of two alcohols
by heating with sulfuric acid; the reaction is one of dehydration. Almost
infinite esters are formed through condensation reaction called esterification
between carboxylic acid and alcohol, which produces water. Alcohols are
important solvents and chemical raw materials. Alcohols are intermediates for
the production of target compounds, such as pharmaceuticals, veterinary medicines,
plasticizers, surfactants, lubricants, ore floatation
agents, pesticides, hydraulic fluids, and detergents.
Carbinol is a primary alcohol with general formula RCH2OH. In carbinol
nomenclature system, the term of carbinol is methanol itself and other groups
are considered to have replaced one of the methanol hydrogen atoms to describe
larger alcohols as derivatives of carbinol. This nomenclature system is
particularly useful when the groups attached to the methanol carbon are large,
aromatic, and cyclo groups. Benzyl alcohol is
called phenylcarbinol or
benzenecarbinol while benzyl carbinol is phenylethyl alcohol.