Purifying impure ORGANIC SOLID

Question 1

Purify organic solid

Answer 1

• Filter off solid.
• Add impure solid into a beaker
• Slowly add a minimum amount of hot solvent to the solid until it dissolves
• Allow the solution to cool, crystals of the desired product will form
• When no more crystals form, filter the crystals under reduced pressure
• Rinse the crystals (cool water), leave to dry

Question 2

Melting Point Determination of Solid

Prep

Answer 2

• Take a capillary tube- hold one end in the hot Bunsen flame
• Rotate until the end of the tube is sealed
• Fill tube with crystals (3mm depth)

Question 3

Use of the Electricity operated thermocycler ting

Answer 3

• Place capillary tube into an ELECTRICALLY OPERATED MELTING POINT APPARATUS
• Tube is inserted into sample hole
• Use the rapid heating setting for first trial
• Once the sample is seen to melt, allow apparatus to cool
• Repeat with gradual heating setting
• As the melting point approaches, set to low and raise temperature slowly whilst observing the sample.

Question 4

Oil Bath setup

Answer 4

• Using an oil bath
• Insert thermometer through a hole in the cork (USE OF THIELE TUBE)
• Slowly heat the side of the arm whilst observing the solid
• When solid starts to melt, record the temperature at which all the solid has melted
• Repeat to ensure accurate + reliable results.