Study of Variations of Concentration, Temperature, and Intermolecular Interactions on the Viscosity of Liquids

A simple extension to the undergraduate laboratory experiment for the determination of viscosity using Ostwald's viscometer is proposed in this work. This fits in well for any undergraduate laboratory demonstration. Ostwald's viscometer is used to investigate the effect of concentration, temperature, and intermolecular interactions on the viscosity of liquids using distilled water as the reference liquid. The viscosity values obtained for acetic acid (v/v%) and sugar solutions (w/v%) have been found to increase with an increase in the concentration of solutions and are synchronous with the literature trends. A drastic decrease in viscosity is observed with an increase in temperature due to a decrease in intermolecular forces of attraction. The temperature variation is found to be a more dominating and contributing factor towards changing viscosity values as compared to the concentration variation. Liquids with stronger intermolecular interactions are found to have greater viscosity values. However, this result was found to be dominated by the factor of greater molecular mass. Nonetheless, the trends obtained in this work are synchronous with literature data.

Automated summary

This study proposes a simple extension to the undergraduate laboratory experiment for viscosity determination using Ostwald's viscometer. It was found that concentration and temperature have a significant impact on viscosity, with temperature variation having a more dominant effect. Liquids with stronger intermolecular interactions have higher viscosity values.