Terms Related to Alcohols
( a) Rectified spirit It contains 95 % ethyl alcohol and 45 % water. It is an azeotrope( constant boiling mixture) and boils at 74 °
( b) Absolute alcohol Alcohol containing no water, i. e; 100 % C2H5OH is known as absolute alcohol. It is prepared as follows.( i) Quick lime process( ii) Azeotropic method
( c) Methylated spirit The rectified spirit rendered poisonous by addition of 4-5 % methyl alcohol, traces of pyridine and some copper sulphate and is known as methylated spirit or denatured alcohol.
( d) Power alcohol Alcohol mixed with petrol or fuel and used In internal combustion engines Is known as power alcohol.
( e) Wood spirit Methyl alcohol( CH3OH) is also called wood spirit. It is obtained by destructive distillation of wood. Pyroligneous add, the product of destructive distillation of wood, contains acetic acid( 10 %), methyl alcohol( 25 %) and acetone( 05 %). Drinking of methanol causes blindness.
( f) Grain alcohol Ethyl alcohol C2H5OH is also called grain alcohol. It is used In the preparation of various beverages containing different percentages.
Dihydric Alcohols
These are generally called glycols because of their sweet taste. Ethylene glycol( CH2OH – CH2OH) is the first and most important member of dihydric alcohol series.
Methods of Preparation