Biophysics Lab 4: Melting Point of Wax

Study Notes

Name: Determination of the Melting Point of Wax
Aim: Determine the melting point of wax.
Theory: Definition, formulas, and units related to the experiment, including phase changes, and how the physical characteristics of a substance change from one form to another.
Tools/Apparatus: Electric heater, thermometer, two calorimeters, and a test tube containing wax.
Method (Procedure):
- Fill half of a larger calorimeter with water.
- Place the calorimeter on an electric heater.
- Add a measured amount of wax to a test tube.
- Place the test tube containing the wax and a thermometer inside the water bath.
- Heat the water bath until the wax completely melts and raises the temperature to about 70°C.
- Carefully remove the test tube from the water bath and allow it to cool.
- Record the temperature of the wax every 30 seconds.
- Plot the temperature-time cooling curve.
- Determine the melting point from the cooling curve.

Dental Applications: Wax is used in dentistry for making molds and models. Understanding its melting behavior helps dental students handle it correctly during procedures.
Laboratory Skills Development: Melting point experiments enhance lab skills, such as heating and temperature control.
Thermal Analysis: This experiment is relevant to thermal analysis, a technique useful in medical research and diagnostics.

Drug Capsules: Some soft gel capsules use wax-like substances in their shells. The melting point ensures the capsule stays intact during storage but dissolves upon ingestion and exposure to body temperature.
Medical Ointments: Wax-like ingredients in topical ointments help maintain a suitable consistency, ensuring spreadability at room and body temperature without melting or becoming too hard.

Bone Wax: Used in surgery to control bleeding from bones. Its melting point ensures it remains solid and effective at body temperature.
Prosthetics and Biomaterials: Understanding the melting point of materials is important in designing prosthetics and implants to withstand body temperatures without deforming.
Orthopedic Casts: Wax or similar materials may be included in coatings for orthopedic casts to provide a moisture barrier, ensuring stability at body temperature during the healing process.

Phase change: a case where the physical characteristics of a substance change from one form to another (e.g., solid to liquid, liquid to gas).
Melting: Solid to liquid.
Freezing: Liquid to solid.
Vaporization: Liquid to gas
Condensation: Gas to liquid
Sublimation: Solid to gas
Deposition: Gas to solid

The heat needed to change the material from one phase to another at a constant temperature

Graph: A graph shows the cooling curve of wax with Temperature (y-axis) and time(x-axis).
Melting Point: The point on the graph where the slope steepens rapidly, marking the transition from solid to liquid.