Introduction of Differential Scanning Calorimetry in a General Chemistry Laboratory Course: Determination of Thermal Properties of Organic Hydrocarbons

Abstract

In first-year general chemistry undergraduate courses, thermodynamics and thermal properties such as melting points and changes in enthalpy (ΔH) and entropy (ΔS) of phase changes are frequently discussed. Typically, classical calorimetric methods of analysis are used to determine ΔH of reactions. Differential scanning calorimetry (DSC) is a rugged, easy-to-use instrumental method for thermal analysis determinations. DSC has become more commonly used in the chemistry curriculum, finding its way into the physical chemistry, analytical chemistry, and even in some general chemistry courses. The work described herein discusses the use of DSC in a general chemistry laboratory course to determine thermal properties such as melting points, ΔfusionH, ΔfusionS, and introduce the concept of polymorphism for organic hydrocarbons.