Using Smartphones to Determine Avogadro Number in the Laboratory By Oil Monolayer Thickness (Benjamin Franklin Experiment)

Nowadays, smartphones and their software play an important role in facilitating the teaching-learning process. Some of these softwires can help a lot in performing tests or analyzing their results. In this study, using a mobile application software, after taking a picture of the surface of the container on which the oil was spread, the Avogadro number was determined by determining the thickness of the oleic acid monolayer. This method of measuring the Avogadro number by imaging the oil stain with a mobile phone and then calculating its level by the software, compared to other physical methods of determining the oil area (such as drawing a shape on glass and then paper) in less time and more accurately is possible. This calculates the area of ​​the oleic acid monolayer accurately. In this method, while performing the classical experiment of measuring Avogadro number by counting method, which is necessary for students' deep understanding of this important physical constant, it is possible to increase the accuracy of calculations and reduce the measurement steps.