Experiments of Modern Chemistry: Simultaneous Recording of Multiple Cooling Curves

An apparatus for simultaneous recording of six heating/cooling curves of metallic mixtures is described. Data are recorded using computer data acquisition and temperature-time data displayed and printed out for evaluation. A reasonable set of data for plotting the phase diagram for the tin-bismuth system can be obtained from heating curves alone in 20 minutes; slightly better data from cooling curves can be obtained in 45 minutes. This allows the experiment to be completed and discussed as part of a single lecture-laboratory period.