How soap is made in laboratory explain in step by step
Answers
Answer:
Soap is formed by mixing fats or oils with strong bases, such as sodium hydroxide. Sodium hydroxide is also called lye. The traditional way to make lye is to leach ashes with water. The ashes contain substantial amounts of sodium hydroxide, which dissolves in the water, forming a solution of sodium hydroxide
Explanation:
Answer:
Saponification
Explanation:
Materials required:
Vegetable oil (castor oil, olive oil, coconut oil or palm oil)
20% sodium hydroxide solution
Common salt
Measuring cylinders
Glass beaker (250 ml)
Blue and red litmus papers
Glass rod
Bunsen burner
Wire gauze
Tripod stand
Filter funnel
Filter paper
Spatula
Knife
Real Lab Procedure:
Take 25 ml of coconut oil in a measuring cylinder and pour it into a 250 ml glass beaker.
Measure 30 ml of 20% NaOH solution in another measuring cylinder and add it into the beaker containing vegetable oil.
Vigorously stir the mixture using a glass rod.
Touch the beaker from outside. It is observed that the beaker is warm.
Place the beaker on a wire gauze placed over a tripod stand.
Heat the beaker using a Bunsen burner till the mixture become a whitish paste.
Remove the beaker from the flame and allow it to cool.
Dip a red litmus paper in the suspension formed.
When dipped in the suspension, the red litmus paper changes its colour to blue.
Dip a blue litmus paper in the suspension.
The colour of blue litmus paper remains the same.
To the above suspension, add 15g of common salt and stir it well with a glass rod.
After adding common salt, soap in the suspension gets precipitated out as solid.
Take a filter funnel and place a filter paper in it and fix it in a stand.
Place a beaker below the funnel.
Pour the contents of the beaker into the funnel over a glass rod and filter the contents of the beaker.
After filtration, soap is left behind in the filter paper.
Transfer the soap into another filter paper using a spatula and dry it by pressing with another filter paper.
Then, cut it into desired shape with a knife.
Simulator Procedure:
To start the simulator, click on the measuring cylinder containing 25 ml coconut oil to pour it into the beaker.
Click on the measuring cylinder containing 30 ml 20% NaOH solution to pour it into the beaker containing coconut oil.
Click on the glass rod to stir the mixture.
Click on the information icon to see the inference.
Click on the 'NEXT STEP' button to go to the next process.
Turn on the burner by clicking on the 'knob' of the burner.
Click on the beaker to place it over the Bunsen burner and heat it.
Click on the information icon to see the inference.
Click on the beaker to place it back from the burner for allowing it to cool.
Turn off the burner by clicking on the 'knob' of the burner.
Click on the 'NEXT STEP' button to go to the next process.
Click on the red litmus paper to dip it into the soap suspension.
Click on the information icon to see the inference.
Click on the blue litmus paper to dip it into the soap suspension.
Click on the information icon to see the inference.
Click on the watch glass containing common salt to add it into the soap suspension.
Click on the glass rod to stir the mixture.
Click on the information icon to see the inference.
Click on the 'NEXT STEP' button to go to the next process.
Click on the beaker to filter the contents.
Click on the spatula to take soap from the funnel.
Click on the filter paper to dry the soap.
Click on the information icon to see the inference.
You can redo the experiment anytime by clicking on the 'Reset' button.
Observations:
When 20% NaOH solution was added to the beaker containing vegetable oil, it was observed that the beaker was warm when touched from the outside.
A whitish suspension was formed by heating the mixture of vegetable oil and 20% NaOH solution.
Red litmus paper changed colour to blue when dipped in suspension. Blue litmus paper was not affected by the suspension.
After adding common salt, the soap in suspension form precipitated out as solid.
Conclusions:
The reaction between vegetable oil and sodium hydroxide solution is exothermic in nature because heat is liberated during the reaction.
The white suspension formed is made up of soap and glycerol. The process of formation of soap is called saponification.
Test using red and blue litmus papers shows that soap suspension is basic in nature and not acidic in nature.
The process of precipitation of soap from the suspension is called salting out.
Precautions:
Do not touch the NaOH solution with bare hands as it may burn the skin.
Do not breathe the fumes of NaOH or let the fumes get in your eyes. Keep the windows of the laboratory open.
The mixture of oil and alkali should be stirred thoroughly.
It is necessary to stir the soap solution after adding common salt to it, in order to precipitate out the soap in solid form.