Determination of the melting enthalpy of a pure substance with CobraSMARTsense

Principle

When a solid melts, energy is required for the destruction of the crystal lattice. A substance whose melting point lies slightly below room temperature is first cooled until it solidifies and then melted in a calorimeter. The melting enthalpy is calculated from the decrease in temperature due to the melting process which is measured in the calorimeter.

Benefits

• Part of a system solution - Easily expandable for further experiments
• Simplified implementation: all pre-settings already prepared
• Calorimeters with particularly high capacitance

Tasks

1. Take a temperature-time-diagram for the melting process of dioxan.
2. Calculate the melting enthalpy and entropy of 1,4-dioxan.

Learning objectives

• Heat capacity
• Melting point
• Latent heat
• Calorimetry
• Gibbs' phase rule
• Enthalpy of sublimation
• Enthalpy of vaporisation

Necessary accessories

• Precision balance 6200g/0.01g

 Software inluded. Computer not provided.