The Mole Concept
The The Mole Concept has at times been seen as a difficult concept to teach. Part of the difficulty may have been linked to the use of the Gas Laws as a fascinating but at the same time somewhat confusing framework for exploring the mole. The pair of programs in this series does not use the Gas Laws as a framework and as well takes a very deliberate approach to the subject with considerable cumulative review. The objective is to provide the necessary material to clearly cover the subject, and to also allow the sets of modules to be used for independent study under less time-constrained circumstances.
The first program, The Need for a Mole, explores the disparity between the macro scale working world of chemistry versus the impossibly small scale of atom-by-atom equations. To develop a foundation for ‘building’ the mole, the program covers understanding of relative atomic mass, together with the complication of differing isotopic masses. Finally, the program undertakes an exploration of a Mass spectrometer for practical determination of relative atomic and isotopic masses.
The second program, Building a Mole, explores the calculation of relative atomic mass, then takes the time to consider the choice of scale and symbol for best representing an enormous number. Avogadro’s Number/Constant are introduced, together with the basis for the experimental determination of the actual figure. The definition of the mole is extended from isotopes and atoms to include any equation fragment, and the calculation of molar mass is demonstrated.