commonly found functional groups

• alkene


  C=C
• alkyne


  C☰C
• aromatic ring 


  benzene
• alcohol


  R-OH
• Ether


  R-O-R
• amine


  R-NH2
• thiol


  R-SH
• aldehyde


  R-CHO
• ketone


  R-CO-R'
• carboxylic acid


  R-COOH
• ester


  R-COO-R'