Density, speed of sound, heat capacity, and related properties of 1-hexanol and 2-ethyl-1-butanol as function of temperature and pressure

The speeds of sound in 1-hexanol and 2-ethyl-1-butanol have been measured over the temperature range from (293.15 to 318.15) K and at pressures up to 101 MPa. The densities have been measured within the temperature range from (283.15 to 343.15 or 353.15) K under atmospheric pressure. For the measurements, a pulse-echo-overlap method and a vibrating tube densimeter have been used. Additionally, in the case of 2-ethyl-1-butanol, the isobaric heat capacities from T = (293.15 to 323.15) K at atmospheric pressure have been measured by means of a DSC calorimeter. The experimental results are then used to calculate the densities and isobaric heat capacities as a function of temperature and pressure by means of a numerical integration technique. The effects of pressure and temperature on these and the related properties are discussed. Densities are correlated by means of the Tait equation.

► Study of the (pVT) relation obtained by acoustic method for 1-hexanol and 2-ethyl-1-butanol.
► Isobaric heat capacities of 2-ethyl-1-butanol measured by means of a DSC.
► Similarity between the behaviour of 1-hexanol and 2-ethyl-1-butanol.
► The magnitude most of the properties: 2-ethyl-1-butanol ⩾ 1-hexanol.
► The temperature-pressure density data correlated by means of the Tait equation.