practical 9

AIM : To determine the melting point of semicarbazone.

MATERIAL REQUIRED:

Semicarbazone compound (sample),Kjeldahl Apparatus,Thermometer,Bunsen burner,Capillary tubes,Safety goggles and gloves.

PROCEDURE:

Sample Preparation:

Weigh the Sample: Use a balance to weigh a small amount (a few milligrams) of the semicarbazone compound.

Sealing of capillary: Use bunsen burner to seal one end of capillary.

Capillary Tube Method: Pack the sample tightly into one end of a thin-walled capillary tube. Tap it gently to ensure it settles.

Set Up the Melting Point Apparatus:

Adjusted Kjeldahl Apparatus in the stand and filled it with sulphuric acid.

Took thermometer, dipped it into sulphuric acid.

Attached capillary to the thermometer.

Moved thermometer slowly into the conical flask so that it could not touches surface of conical flask and could not move the capillary.

Heating:

Gradually heat  the sample, ensured even heating all over the apparatus.

Monitored the temperature closely in the thermometer.

Observe the Melting Process:

As the temperature rises, first signs of melting showed (the compound changed to liquid).

Recorded the temperature at which the sample first begins to melt (this is the melting point).

Repeat:

For accuracy, i repeated the experiment 2-3 times with fresh samples to confirm the melting point.

Clean Up:

Dispose of the samples and clean your workspace according to safety guidelines.

OBSERVATION :-

Sample 1: 

Sample 2:  

Sample 3:  

Average melting point : 

RESULT-

PRECAUTIONS-

1.)Wear safety goggles and gloves throughout the experiment.

2.)During heating sand bath must be present below bunsen burner as precaution.

3.)The capillary must be sealed completely for accurate melting point.