Question

For determining the saponification reaction for the preparation of soap,the apparatus we required are

Answer 1

Answer:

Materials Required:

1) Fats and Oils [coconut oil, sunflower oil]

2) Conical Flask

3) 100ml beaker

4) Weigh Balance

5) Dropper

6) Reflux condenser

7) Boiling Water bath

8) Glass pipette (25ml)

9) Burette

Reagents Required:

1) Ethanolic KOH(95% ethanol, v/v)

2) Potassium hydroxide [0.5N]

3) Fat solvent

4) Hydrochloric acid[0.5N]

5) Phenolphthalein indicator

Procedure:

1) Weigh 1g of fat in a tared beaker and dissolve in about 3ml of the fat solvent [ ethanol /ether mixture].

2) Quantitatively transfer the contents of the beaker three times with a further 7ml of the solvent.

3) Add 25ml of 0.5N alcoholic KOH and mix well, attach this to a reflux condenser.

4) Set up another reflux condenser as the blank with all other reagents present except the fat.

5) Place both the flasks in a boiling water bath for 30 minutes .

6) Cool the flasks to room temperature .

7) Now add phenolphthalein indicator to both the flasks and titrate with 0.5N HCl .

8) Note down the endpoint of blank and test .

9) The difference between the blank and test reading gives the number of millilitres of 0.5N KOH required to saponify 1g of fat.

10) Calculate the saponification value using the formula :

Saponification value or number of fat = mg of KOH consumed by 1g of fat.

Weight of KOH = Normality of KOH * Equivalent weight* volume of KOH in litres

Volume of KOH consumed by 1g fat = [Blank – test]ml