A brief overview of CHEMEX--a problem-solving, tutorial style computer-assisted instructional course--is provided and sample problems are offered. In CHEMEX, students receive problems in advance and attempt to solve them before moving through the computer program, which assists them in overcoming difficulties and serves as a review mechanism. Problems based upon those contained in the booklet "Chemical Calculations: An Audiotutorial Approach" and covering the following topics are currently available in CHEMEX: 1) units and conversion factors, figures, temperature, and density; 2) atomic and molecular weights; 3) chemical equations, stoichiometry, and balancing; 4) simple chemical reactions: ions, acids, oxidation number, properties and oxides, hydroxides, hydrides of the elements; 5) solutions, concentration, dilution, and titration; 6) oxidation-reduction equations; 7) properties of gases; 8) solubility product calculations; and 9) acids, bases, and pH calculations. CHEMEX is written in Coursewriter III, Version 2 and supported on the IBM 360/370 systems. (For related document, see EM 011 373.) (PB)