Monday, May 25, 2009

Oil and water don't mix! Entropy of mixing

In tomorrow's lecture I will talk about immiscible liquids. This shows the importance of entropy of mixing. The temperature-composition phase diagram of two partially immiscible liquids has a critical point. There is a nice video of the critical opalescence associated with the critical point for the cyclohexane-methanol mixture. An Excel spreadsheet for the thermodynamic data is here.

The simple analytical formula for mixing of a regular solution shows how the competition between energy and entropy which drives phase transitions.

1 comment:

  1. My father got very worried when I explained to him that the orientability of a cellular surface - on which our existence as thinking salt-water bags relies - was due to no stronger interaction than the separation of salad dressing.