Abstract
The isobaric heat capacities of liquid ethanol are measured. Our group constructed a flow-calorimeter in 1996 for measuring specific heat-capacity at constant pressure of liquid refrigerants. Moreover, improvement of apparatus is continuously conducted. In 2008, Suzuki reconstructed the apparatus of a flow calorimetry and stable mass flow rate became possible. And isobaric heat capacities of ethanol are measured by using this apparatus. The measurements obtained 8 points at the temperature range from 280 to 320 K and at pressures 500 kPa. And uncertainty for heat capacity is estimated to be from 0.59% to 0.69% .Because we confirmed that the apparatus is able to measure isobaric heat capacities without influence of heat loss and to get the repeatability within the uncertainty, we are sure that our measurements are reliable value. For more careful consideration, we measured two different samples of ethanol under the same conditions. Even after replacing sample, measured value is within the uncertainty. And we also measured isobaric heat capacity of ethanol in lower temperature range. The measurements don't perfectly agree with existing measurements or derived specific-heat-capacity values from existing equation of state developed by Dillon and Penoncello within the uncertainty. We believe our measurements to be much reliable, although we are currently checking the reliability by further measurements.
