Measuring Vapor Pressure with an Isoteniscope: A Hands-On Introduction to Thermodynamic Concepts

Abstract

Characterisation of the vapour pressure of a volatile liquid or azeotropic mixture, and its fluid phase diagram, can be achieved with an isoteniscope and an industrial grade digital pressure sensor using the experimental method reported in this study. We 10 describe vapour-pressure measurements of acetone and n-hexane and their azeotrope, and how the data can be used to calculate thermodynamic properties of the test liquids, such as the molar heat of vaporisation. This hands-on experience allows students to appreciate important thermodynamic concepts such as phase equilibrium, preparing them for more-advanced studies of the subject. 15ABSTRACT GRAPHIC

History repeats itself again: Will the mistakes of the past for ILs be repeated for DESs? From being considered ionic liquids to becoming their alternative: the unbalanced turn of deep eutectic solvents

“…The isoteniscope is the most commonly used method to measure vapor pressure. 54 Despite the recent redesigns of the apparatus, 55 this procedure is very demanding regarding the manipulation of the apparatus and requires large volumes of the sample under study. Thus, recently, this method has been replaced by head-space gas chromatography mass spectrometry (HS-GC-MS), for DESs and ESs, and thermogravimetric analysis (TGA) mainly for ILs.…”

A Framework for Learning in the Chemistry Laboratory

“…A way to avoid this is to instead ask students to compare values obtained within an experiment. We have modified typical vapour pressure experiments, for example, so that instead of asking students to determine the vapour pressure of a liquid and compare it to the literature, we ask them to hypothesise what difference they expect between the liquids, and perform an experiment to see if their hypothesis is borne out.…”

Creating a Confident and Curious Cohort: The Effect of Video-Led Instructions on Teaching First-Year Chemical Engineering Laboratories

“…Although hands-on laboratory modules have clear benefits for learners, educators are often deterred by the resource intensive nature of such modules. As shown in previous case studies, 3,14 the development and delivery of hands-on laboratory modules require human time and expertise, equipment and consumables. Strategies that reduce the requirement of any input while ensuring learning quality will lower the barrier of adoption for educators.…”