Ronald L. Rich 112 S. Spring St., Bluffton, OH 45817 Chemical notation and terminoloev -, are beset with various problems, both in the traditional reprrsentations of quantities and units ( 1 - 5 1 and in thr 51 reoresentations (6.8,. A cold war seems to sputter along. Let us examine, with sp&ial attention to concentration, whether atruce could be promoted, mainly by filling a chemical gap in the Syst&meInternationale. The promoters of SI complain about our use of the term "concentration" itself. They ask how we can justify reporting a single physical quantity both as so many moles per liter (e.g., 2.0 molar) and as so many moles per kilogram (e.g., 2.1 molal) using dimensionally independent units. T o avoid this, we are urged to distinguish the two quantities, concentration and molalitv. This is common sense in one way, but too bad in another. Our purpose in both cases is t o express the amount of solute in some quantity of solvent or solution. The title of this article might seem to lose as much as i t would gain as "SI and Non-SI Units of Concentration and Molalities . . . ". Perhaps, just as "phenol" may mean either a specific substance or any member of a class, we can continue sometimes to use "concentration" with a broad meaning in general discussions but a specific one when called for. In the rest of this paper, however, we wish to meet a concern of the SI people by using our terms more wreciselv. On the other hand, a s&ious defect of SIfor chemists is the continuing lack of a swecial name and svmbol for the coherent unit of concentration. Here we wishto offer some candidates, together with related suggestions for molalitv. We can use the same unit,-
