Resumen de Quantifying Meniscus Forces with an Electronic Balance: Direct Measurement of Liquid Surface Tension. A Physical Chemistry Experiment
The phenomenon of capillary adhesion, in which a drop of liquid placed between two solid surfaces attracts them together, is considered at an elementary level. It is shown that for a small amount of liquid, independent of the solids-contact geometry, the adhesion force is defined mainly by the Laplace pressure force FL, for which a generalized equation is derived under arbitrary contact geometry. A simple physical chemistry laboratory experiment for measuring FL between a glass sphere and a glass plate with an ordinary electronic balance is described. The relationship between FL and liquid surface tension γ is used to obtain γ. The validity and acceptability of this method for undergraduate physical chemistry laboratories is experimentally confirmed for various liquid samples.
