School of Physics Lecture Demonstration Manual

Fb-10 Surface Tension of Aqueous Solutions

Published: Friday 10 March 2006 - Updated: Tuesday 29 March 2011


To demonstrate that in general organic substances dissolved in water lower the surface tension.



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Surf Ten of Aqu Solutions Diagram


If a piece of camphor is scraped into a dish full of water it will dart over the surface in a seemingly random manner.

Camphor is only slightly soluble in water. On an uneven piece of camphor, solution occurs more rapidly at a point P than where the surface is smooth. The strength of the camphor-water solution near P is greater than at any other point and hence the surface tension is least at P. THerefore the greater tensions on the other side pull the camphor away from P.

Safety notes

Electrical Safety 

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