Standard electrode potentials E° of Ag-AgC1 electrode in molality scale and acidity constants of glyeine pK_1° at constant molality of NaCl (1.0 mol·kg^(-1)) in 5 and 15 mass% glucose-water mixed solven...Standard electrode potentials E° of Ag-AgC1 electrode in molality scale and acidity constants of glyeine pK_1° at constant molality of NaCl (1.0 mol·kg^(-1)) in 5 and 15 mass% glucose-water mixed solvents over a range of temperatures from 278.15 to 318.15 K were determined from precise emf measurements.The dependence of acidity constant on temperature is given as a function of the thermodynamic temperature T by an empirical equation, pK_1° =A_1(K/T)-A_2+A_3(T/K).The corresponding thermodynamic quantities of the first dissociation process of glycine were calculated and the effects of both tho solvent and the salt on them were also discussed.展开更多
Ultrasonic speeds of 4-aminobutyric acid in 0.0041,0.0125 and 0.0207 mol·kg^-1 aqueous salbutamol sulphate（SBS） solutions are measured at 308.15,313.15 and 318.15 K.Isentropic compressibility kS,change in isent...Ultrasonic speeds of 4-aminobutyric acid in 0.0041,0.0125 and 0.0207 mol·kg^-1 aqueous salbutamol sulphate（SBS） solutions are measured at 308.15,313.15 and 318.15 K.Isentropic compressibility kS,change in isentropic compressibility△k S,relative change in isentropic compressibility（ △kS /kS^0） ,apparent molal compressibility kφ,limiting apparent molal compressibility kφ^0 ,transfer limiting apparent molal compressibility k φ^0,hydration number nH,pair and triplet interaction parameters kAS,kASS are estimated.The above parameters are used to interpret the solute-solute and solute-solvent interactions of 4-aminobutyric acid in the aqueous salbutamol sulphate solutions.展开更多
Density（ρ）and viscosity（η）are measured for glycine,DL-α-alanine DL-α-valine,and DL-α-leucine in 0.05,0.10,0.15 and 0.20 mol·L^-1aqueous metformin hydrochloride at 308.15,313.15 and 318.15 K.The measured ...Density（ρ）and viscosity（η）are measured for glycine,DL-α-alanine DL-α-valine,and DL-α-leucine in 0.05,0.10,0.15 and 0.20 mol·L^-1aqueous metformin hydrochloride at 308.15,313.15 and 318.15 K.The measured values are used to estimate some important parameters,such as partial molal volume Vφ,standard partial molal volume Vφ^0,transfer volume ΔVφ^0,hydration number nH,the second derivative of infinite dilution of partial molal volume with respect to temperature,viz., ^2 Vφ^0 /T^2,viscosity B-coefficient,variation of B with temperature,viz., dB/dT,free energy of activation per mole of solvent Δμ1^＊0 and solute Δμ2^0＊ of the amino acids.These parameters are interpreted in terms of solute-solute and solute-solvent interactions and structure making/breaking ability of solutes in the given solution.In addition,Vφ^0,0 ΔVφ^0,viscosity B-coefficient,ΔB and Δμ2 ^0＊ are split into group contributions（NH3^＋ COO ^-）and -CH2 of the amino acids using their linear correlation and their behavior is discussed.展开更多
基金Project supported by the National Natural Science Foundation of China.
文摘Standard electrode potentials E° of Ag-AgC1 electrode in molality scale and acidity constants of glyeine pK_1° at constant molality of NaCl (1.0 mol·kg^(-1)) in 5 and 15 mass% glucose-water mixed solvents over a range of temperatures from 278.15 to 318.15 K were determined from precise emf measurements.The dependence of acidity constant on temperature is given as a function of the thermodynamic temperature T by an empirical equation, pK_1° =A_1(K/T)-A_2+A_3(T/K).The corresponding thermodynamic quantities of the first dissociation process of glycine were calculated and the effects of both tho solvent and the salt on them were also discussed.
文摘Ultrasonic speeds of 4-aminobutyric acid in 0.0041,0.0125 and 0.0207 mol·kg^-1 aqueous salbutamol sulphate（SBS） solutions are measured at 308.15,313.15 and 318.15 K.Isentropic compressibility kS,change in isentropic compressibility△k S,relative change in isentropic compressibility（ △kS /kS^0） ,apparent molal compressibility kφ,limiting apparent molal compressibility kφ^0 ,transfer limiting apparent molal compressibility k φ^0,hydration number nH,pair and triplet interaction parameters kAS,kASS are estimated.The above parameters are used to interpret the solute-solute and solute-solvent interactions of 4-aminobutyric acid in the aqueous salbutamol sulphate solutions.
文摘Density（ρ）and viscosity（η）are measured for glycine,DL-α-alanine DL-α-valine,and DL-α-leucine in 0.05,0.10,0.15 and 0.20 mol·L^-1aqueous metformin hydrochloride at 308.15,313.15 and 318.15 K.The measured values are used to estimate some important parameters,such as partial molal volume Vφ,standard partial molal volume Vφ^0,transfer volume ΔVφ^0,hydration number nH,the second derivative of infinite dilution of partial molal volume with respect to temperature,viz., ^2 Vφ^0 /T^2,viscosity B-coefficient,variation of B with temperature,viz., dB/dT,free energy of activation per mole of solvent Δμ1^＊0 and solute Δμ2^0＊ of the amino acids.These parameters are interpreted in terms of solute-solute and solute-solvent interactions and structure making/breaking ability of solutes in the given solution.In addition,Vφ^0,0 ΔVφ^0,viscosity B-coefficient,ΔB and Δμ2 ^0＊ are split into group contributions（NH3^＋ COO ^-）and -CH2 of the amino acids using their linear correlation and their behavior is discussed.
