What is the total number of hydroxyl groups in propane-1,2,3-triol?
Propane-1,2,3-triol (glycerol, CH₂OH-CHOH-CH₂OH) has three -OH groups, as indicated by ‘triol’ in its name.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Physical Properties and Acidity of Alcohols and Phenols