Requirements (Instruments, Chemicals & Other) :

1. Polenske flask (310 ± 10 ml volume)
   
2. Graduated cylinders (25 ml and 100 ml)
   
3. Pipette (50 ml)
   
4. Distillation apparatus (Polenske distillation setup)
   
5. Burette (50 ml, graduated to 0.1 ml)
   
6. Conical flasks (250 ml)
   
7. Glass funnel
   
8. Whatman filter paper (Grade 4)
   

Reagents :

1. Glycerol (98%)
   
2. Sodium hydroxide solution (50%)
   
3. Dilute sulfuric acid (1:1)
   
4. Ethanol (95%)
   
5. Phenolphthalein indicator (0.5% solution in ethanol)
   
6. 0.1N Sodium hydroxide or Barium hydroxide solution
   
7. Silver sulphate
   

Procedure :

Saponification Steps :
1. Take two 300 ml distilling flasks marked as blank (B) and sample (S) and add 5 g of ghee into the “S” flask.
2. Add 20 g of glycerol and 2 ml of 0.5N NaOH solution in both the flask.
3. Heat both the flask over the heating mantle with stirring until the sample is completely saponified and clear.

Distillation Steps :
4. Add 93 ml of boiling distilled water in both the flask and dissolve properly.
5. Add 50 ml of 1.0 N sulfuric acid in both the flask
6. Connect the flask “S” to the distillation apparatus.
7. Distil 110 ml of distillate in 19-21 minutes.
8. Connect the flask “B” to the distillation apparatus and collect 110 ml distillate

Filtration and Titration :
9. Filter both the distillate separately through Whatman filter paper (Grade 4).
10. Take out 100 ml filtrate of the flask “S” in a conical flask and titrate with 0.1N NaOH using 0.1 ml of phenolphthalein indicator until a persistent pink color appears (R.M. Value). (T1)
11. Take out 100 ml filtrate of the flask “B” in a conical flask and titrate with 0.1N NaOH using 0.1 ml of phenolphthalein indicator until a persistent pink color appears (R.M. Value). (T3)
12. Wash the residue of flask “S” with 50 ml of hot 95% ethanol and titrate with 0.1N NaOH using 0.1 ml of phenolphthalein indicator to determine the Polenske value. (T2)
13. Wash the residue of flask “B” with 50 ml of hot 95% ethanol and titrate with 0.1N NaOH using 0.1 ml of phenolphthalein indicator to determine the Polenske value. (T4)

Calculations :

1. Reicher-Meissl value=1.10 (T1-T2)
   
2. Polenske value=(T3-T4)
   Where,
   T1 = Volume (ml) of 0.1N NaOH used for the sample for Reicher-Meissl value
   T2 = Volume (ml) of 0.1N NaOH used for blank.
   T3 = Volume (ml) of 0.1N NaOH used for the sample for Polenske value
   T4 = Volume (ml) of 0.1N NaOH used for blank.