The organic compound that is formed after one or more hydrogen molecules are replaced by hydroxyl groups. Hydrogen on the rings of aromatic hydrocarbons is replaced by hydroxyl groups and the resulting compounds are not alcohols but phenols.
Existence of ALCOHOL
There are many kinds of alcohols in nature, including ethanol and other alcohols of the same series. There are many kinds of terpenes and aromatic alcohols in plant essential oil. Many alcohols are found in animal and plant oils, fats, and waxes in the form of esters.
Classification of ALCOHOL
According to the amount of hydroxyl, it can be divided into one, two, three or more alcohols. Generally, a carbon atom cannot contain two hydroxyl groups, which are unstable with the geminal diol and easy to lose water and form carbonyl compounds. Alcohols can also be divided into primary alcohols, secondary alcohols, and tertiary alcohols according to the number of hydrogens on the carbon atoms that connect hydroxyl groups.
Nature of ALCOHOL
Generally, alcohols are colorless liquids or solids, and monovalent carboxyl alcohols containing less than 12 carbon atoms are liquids, 12 or more are solids, and polyols (such as glycerol) are syrups. Unary alcohols are soluble in organic solvents, and alcohols below three carbons are soluble in water. The melting and boiling points of the lower alcohols are much higher than those of the hydrocarbons with the same number of carbon atoms, because of the presence of hydrogen bonds in the alcohol molecules, which are used for association. Saturated alcohol does not discolor bromine. The alcohols are active, and the carbon-oxygen bonds and hydrogen-oxygen bonds are polar bonds. Hydrogen-oxygen bond fracture and carbon-oxygen bond fracture can be carried out with the hydroxyl group as the center. In addition, carbon atoms linked to hydroxyl groups are easily oxidized to form aldehydes, ketones
, or acids