UIUC Physics Lecture Demo: Clear, then Colored Water

UIUC Physics
Lecture Demonstration
Database

Demo # 344

Clear, then Colored Water

ID # 344

Description:

A few drops of blue dye are dropped into water. The dye mixes with the water. This is an irreversible process because the dye cannot "unmix" with the water. Thus, the entropy of the universe is increased.

Picture of Clear, then Colored Water

Physics Concept:

Thermodynamics and Statistical Mechanics
Entropy and the Second Law of Thermodynamics
Entropy

The demonstration takes about 1 minute to perform.