Aim : To determine the boiling point of given liquid organic compound.
Apparatus : Thiele's tube. fusion tube, capillary tube, thermometer, thread.
Chemical : Given organic liquid compound, paraffin liquid.
Theory :
1) The boiling point of liquid substance is defined as the temperature at which vapour pressure of liquid is equal to atmospheric pressure.
2) The boiling point of liquid substance is to be taken to check the purity of liquids.
Generally pure liquids boils at fixed temp.
Procedure :
1) The Thiele's tube containing paraffin liquid of fix to the stand as shown in diagram.
2) Fix fusion tube to thermometer using thread. Take few drops of given liquid compound into fusion tube whose boiling point is to be determined. The closed end of fusion tube and mercury bulb of thermometer should lie in same line.
3) Take capillary tube closed at one end and keep into fusion tube in inverted fusion.
4) Immerse thermometer along with fusion tube and capillary tube into Thiele's tube containing Paraffin liquid. Here the open end of fusion tube should not dip into paraffin liquid.
5) Heat Thiele's tube gently.
Record the temperature, when the rate of bubbling is maximum. This temperature is called boiling point of that liquid.
6) In higher boiling point compounds during heating first of all liquid compound inserts or enters into capillary tube and then starts maximum bubbles. This temperature is the boiling point of that liquid compound.
Result :
1) The boiling point of compound
I) is 76°C
2) The boiling point of compound
II) is 120°C
3) The boiling point of compound
III) is 180°C
They compound is first is Ethyl alcohol [ ethanol]
They compound seconds is acetyl acid [ ethanoic acid]
They compound third is Aniline [ benzamine ]