ALCOHOL NOTES ORGANIC CHEMISTRY

❖ ALCOHOLS
• INTRODUCTION:
• Organic compounds in which – OH (Hydroxyl) group i
directly bonded to C – atom of alkyl group.
• Classification:
• Based on number of – OH group present in the molec
formula of alcohol, alcohols are of
1) Monohydric alcohols
2) Dihydric alcohols
3) Trihydric alcohols &
4) Polyhydric alcohols
1/5/2022 PRAKASH POUDEL

, 1. Monohydric alcohols:
• They have only one – OH group in their molecular formul
• They are represented by R-OH, where, R = Any alkyl grou
• They have general molecular formula CnH2n+1OH or CnH2n
Where, n = No. of C- atom.
For example:
CH3 - OH CH3 -CH2-CH2-OH
Methanol Ethanol Propan-1-ol
(Methyl alcohol) (Ethyl alcohol) (n-propyl alcohol)

CH3 -CH2-CH2-CH2-OH
Propan-2-ol Butan-1-ol Butan-2-ol
(isopropyl alcohol) (n-butyl alcohol) (sec.butylalcoho
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,2-methyl propan-1-ol
(isobutylalcohol) 2-methylpropan-2-ol 2,2-dimethylpropa
(t-butylalcohol) (neopentylalco
2) Dihydric alcohols:
• They have two –OH groups in their molecular formula but
the –OH groups are bonded to different C-atoms.
• They have general molecular CnH2n+2O2.
• For examples:

Ethane-1,2-diol
(Ethylene glycol)
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, 3) Trihydric alcohols:
• They have three – OH groups in their molecular formula
but the –OH groups should be bonded to different C-
atoms.
• They have general molecular formula CnH2n+2O3
For examples:




Propane-1,2,3-triol
(Glycerol)
1/5/2022 PRAKASH POUDEL