VPB 112: General Veterinary Biochemistry (1+1)

ESTIMATION OF ACID NUMBER OF AN OIL - PROCEDURE

• Weigh a clean and dry 100 mL conical flask: (W₁).
• Pipette out 5 mL of oil into it and weigh again: (W₂).
• (W₂) - (W₁) gives the weight of the oil taken.
• Add 20 mL of neutral alcohol into conical flask.
• Heat the contents to boiling in a hot water bath (do not use an open flame).
• Titrate the hot solution against the 0.1 N KOH using phenolphthalein as indicator.
• The end point is the appearance of the pale pink color, which persists for half a minute.
• Record the volume of KOH consumed. Repeat the experiment for concordant value.