COMBUSTION CALORIMETRY OF ORGANIC BROMINE COMPOUNDS: THE ACCURACY OF DATA OBTAINED WITH A MOVING-BOMB TECHNIQUE

A moving-bomb calorimetric method for measuring heats of combustion at 25°C of solid and liquid organic bromine compounds has recently been developed". The calorimetric system is calibrated by combustion of standard benzoic acid under certified bomb-calibrating conditions. In order to obtain well-defined equilibrium final states in the bomb in combustion experiments with bromine compounds, however, the bomb liquid must differ both in nature and amount from that specified for calibration experiments with benzoic acid. Thus, 3 g of water per litre of bomb volume are used in the calibration experiments, whereas 112 g of 0·06 M arsenious oxide solution per litre of bomb volume are used in the combustion experiments with bromine compounds. Calibration experi-ments with benzoic acid and combustion experiments, with paraffin oil and with p-bromobenzoic acid have all given results of a precision slightly better than 0·01 per cent. This demonstrates that the various additional complications introduced into the procedure by the presence of a reasonabl