Experiment 15: Entropy changes in physical processes

Entropy of vaporisation of a volatile liquid.

Notes

Entropy can be loosely described as the degree of disorder of a system. When a liquid is at its boiling point it is in equilibrium with its vapour at atmospheric pressure. According to the relationship:

ΔG = ΔH + TΔS

The value of Gibbs free energy of a process at equilibrium is zero, hence using the enthalpy of vapourisation of the liquid, ΔH(vap), from a data source allows us to find the entropy change for the vapourisation process.

Instructions

Sivolivovs methos for b.p. determination

Experimental report

The following factors must be considered:

• Accurate recording of raw data

Assessment

• Data collection and processing