A sample of soap was prepared in the school laboratory by the reaction between two substances, X and Y - Leaving Cert Chemistry - Question 1 - 2013

To accurately copy the diagram, one should include features such as:

• Still head
• Condenser
• Thermometer
• Flask containing reaction mixture
• Antibumping granules
• Adapter
• Beaker collecting distillate
• Water out pipe These parts should be labeled clearly to indicate their functions in the distillation process.

To ensure smooth boiling, antiebumping granules could have been added to the flask. These help to create a more uniform boiling surface and prevent the boiling liquid from bumping, which can cause the mixture to splash out.

Ethanol, which was used as the solvent in the reaction mixture, was the substance removed by distillation. The distillation process allows for the separation of this volatile component from the less volatile components.

Brine refers to a concentrated solution of salt in water, typically consisting of sodium chloride (NaCl).

The precipitate of soap was removed from the brine through a process such as filtration or decanting. This method allows the solid soap to be separated from the liquid brine efficiently.

Washing the soap was necessary to:

• Remove any unreacted sodium hydroxide that could cause skin irritation.
• Clean the soap of impurities formed during the reaction or present in the brine.

Warm water should not have been used because it could dissolve more soap, making it less effective in removing impurities. Using cold water helps to rinse without losing the soap itself.