Melting Point of an Organic Compound - MeitY OLabs

Learn that melting point is the temperature at which a solid converts to liquid at one atmosphere pressure. Understand the molecular process where heat causes decreased intermolecular forces and molecular separation.

Seal one end of the capillary tube by heating in a Bunsen burner flame. Push the open end into powdered naphthalene on a glass plate, then gently tap the sealed end to fill the tube to 2-3 mm height.

Secure the filled capillary tube to the thermometer using thread to hold them together as a single unit.

Place the 100 ml beaker containing liquid paraffin on the hot plate. Clamp the thermometer with attached capillary tube to an iron stand and immerse both into the paraffin bath.

Slowly heat the liquid paraffin bath while gently stirring with a stirrer to ensure uniform heating. Note temperature t1 when the naphthalene inside the capillary begins to melt.

Continue heating the bath and note temperature t2 when all naphthalene in the capillary tube is completely melted. Calculate the melting point as the average of t1 and t2.

Use dry, finely powdered naphthalene packed uniformly without air gaps. Heat the paraffin bath slowly with gentle stirring, ensuring the thermometer bulb and capillary do not touch the beaker sides or bottom.