Experimental Study of the Thermodynamic Properties of Diethyl Ether (DEE) at Saturation

摘要: The isochoric heat capacities \({({C_{V1}^{\prime}} ,{C_{V1}^{\prime\prime}},{C_{V2}^{\prime}},{C_{V2}^{\prime\prime}})}\), saturation densities (\({\rho _{\rm S}^{\prime}}\) and \(({\rho_{\rm S}^{\prime\prime})}\)), vapor pressures (P S), thermal-pressure coefficients \({\gamma_V=\left({\partial P/\partial T}\right)_V}\), first temperature derivatives of the pressure γ S = (dP S/dT) diethyl ether (DEE) on liquid–gas coexistence curve near critical point have been measured with a high-temperature high-pressure nearly constant-volume adiabatic piezo-calorimeter. measurements ,{C_{V1}^{\prime\prime}},{C_{V2}^{\prime}},{C_{V2}^{\prime\prime}})}\) were made in liquid one- two-phase regions along curve. calorimeter was additionally supplied calibrated extensometer to accurately simultaneously measure PVT, C V VT, coefficient, , carried out range from 416 K 466.845 (the temperature) for 17 212.6 kg · m−3 534.6 m−3. quasi-static thermo- (reading PRT, T − τ plot) baro-gram (readings tensotransducer, P techniques used phase-transition parameters ,ρ ,T S) . total experimental uncertainty density (ρ (T estimated be 0.02 % 0.05 %, 15 mK, 2 3 0.12 1.5 respectively. values saturated caloric thermal S, ρ properties calculate other derived thermodynamic W, int, ΔH vap, \({\left({\partial V/\partial T}\right)_P^{\prime}}\) DEE point. second pressure, (d2 S/dT 2), chemical potential, μ/dT also calculated directly 2) calorimetric compared vapor–pressure equations. interpreted terms “complete scaling” theory phenomena. In particular, effect Yang–Yang anomaly strength R μ coexistence-curve diameter behavior studied. Extended scaling-type equations (T), as function developed.