Abstract: An isoperibel calorimeter for measnring heat of solid-liquid, liquid-liquid reactions was developed. Rection vessel made by resisting hard glass, its volume is about 100 cm~3, The precisions of cotrolling and measuring the tempreture were±0.001 K and ±0.0001 K respectively. The measnring error was 0.5%. The measured enthalpy of solution KCl in water at 298.2 K was 17597±17 J·mol~(-1), enthalpy of reaction of THAM (from NBC-724a in USA) in 0.1000 mol·L~(-1) HCl at 298.2 K was -29779±16J·mol~(-1). The values are in well agreement with the published results. The relability of this calorimeter has been confirmed.

Key words: Themochemistry, Calorimetry, Calorimeter