Determination of saponification value of the given oil/fat

BACKGROUND

Principle: Saponification value is defined as the number of milligrams of KOH required to completely hydrolyse (saponify) one gram of the oil/fat. In practice a known amount of the oil or fat is refluxed with excess amount of standard alcoholic potash solution and the unused alkali is titrated against a standard acid.¹

Aim: To determine saponification value of the given oil/fat.

Reaction:

REQUIREMENTS

Sample:        Oil or fat

Apparatus:    Conical flask

Reflux and condenser

Water bath

Burette and Pipette

Chemical:  0.5 N HCl

phenolphthalein

0.5 N alcoholic potassium-hydroxide solution

PROCEDURE

About 2 g of the given oil or fat is taken in a conical flask but weighed accurately (w g). The oil/fat is dissolved in 25 ml of 0.5 N alcoholic potassium-hydroxide solution. Then the reaction mixture is refluxed using a water condenser on a water-bath for half an hour. The resulting solution is cooled and titrated against a 0.5 N HCl solution adding 1 ml of phenolphthalein. The number of ml of acid required is noted (a). An exactly identical blank experiment (leaving the fat or oil) is performed. Number of ml of hydrochloric acid required is noted (b).

Observation

	Samples No.	Initial Burette Reading (ml)	Final Burette Reading (ml)	Difference (ml)	Average (ml)
For Excess KOH remaining	1				a =
	2
For Blank	1				b =
	2

Calculation

CONCLUSION

Saponification value of the given oil/fat is …….

REFERENCES

1. Advanced Practical Organic Chemistry by O. P. Agarwal; Published by Krishna Prakashan Media (P) Ltd; Page No. 275
2. Indian Pharmacoepia 2010, Part I; Page No. 93
3. Practical Pharmacognosy by Saroja Joshi and Vidhu Aeri; Published by Frank Bros . & Co. (Publishers) Ltd.; First Edition: 2009; Page No. 296
   

Also read:

• Determination of saponification value of fat (coconut oil)
• Protein denaturation by egg albumin method (in vitro)
• Analgesic activity study of drugs by hot plate (Eddy’s hot plate) method
• Study of local anesthetics by Infiltration anaesthesia in guinea pig
• Study of local anesthetics by Surface anaesthesia on the cornea of rabbits
• Study of local anesthetics by Spinal anaesthesia in rats
• Study of local anesthetics by conduction anaesthesia in frogs
• Study of biotransformation and excretion of drug

🔴 Would you like to attempt Labmonk Daily quiz? Click here

🔵 Check out Jobs & Exam Notices. Labmonk Notice Board

🔴 Labmonk Scholarships. Click here

🔵 Labmonk Blog. Click here

🔴 Do you need notes? Click here

🔵 Watch Career related videos on Youtube: Watch now !!

🔴 Would you like to answer Labmonk quiz?  Click here