Marzena Dzida, Mirosław Chorążewski University of Silesia, Institute of Chemistry, Szkolna 9, Katowice The effect of temperature and pressure on the thermodynamic and acoustic properties of pentanols at temperatures from (293 to 318) K and pressures up to 100 MPa

Investigated alcohol CH 3  CH 2  CH 2  CH 2  CH 2  OH pentan-1-ol CH 3  CH 3  CH 2  C  CH 3  OH 2-methyl-2-butanol CH 3  CH 3  CH 2  CH  CH 2  OH 2-methyl-1-butanol CH 3  CH 2  CH  CH 2  CH 3  OH pentan-3-ol

Aim: Study of the influence of the structure of the alcohol and the position of the hydroxyl group in the alcohol molecules on temperature and pressure dependence of the thermodynamic properties

Physicochemical properties of isomeric pentanols at K 2-methyl-1-butanol pentan-1-ol 2-methyl-2-butanol pentan-3-ol K b.p. / 0 C  H vap / kJ mol C p / J mol -1 K  / kg m  r  / D g k

Ultrasonic speed measurements temperature range 293 – 318 K pressure range 0.1 – 100 MPa method pulse-echo-overlap accuracy  0.5 m s -1 (0.1 MPa);  1 m s -1 (p  0.1 MPa) Density measurements temperature range 293 – 318 K pressure 0.1 MPa method vibrating-tube densimeter (Anton Paar DMA 5000) accuracy 0.05 kg m -3 Heat capacity measurements temperature range 284 – K pressure 0.1 MPa method differential scanning calorimeter Micro DSC III (University of Łódź) accuracy 0.25 % Experiment

High pressure ultrasonic cell (1)pressure chamber (2)plug (3)transducer (4)reflector (5)acoustic tube (6)high pressure capillary (7)high pressure cable Żak A., Dzida M., Zorębski M., Ernst S., A high pressure system for measurements of the speed of sound in liquids, Rev. Scient. Instr. (2000) 71, Dzida M., Chorążewski M., Zorębski M., Mańka R., Modification of a high pressure device for speed of sound measurements in liquids, J. de Physique IV (2006) 137,

Speeds of sound in 2-methyl-1-butanol plotted against temperature at elevated pressures: (●) 0.1 MPa, (▲) MPa, (■) MPa, (  ) MPa

Determination of the p  T data by the acoustic method Isothermal compressibility is related to isentropic one by the following relationship: where Laplace formula:

Temperature dependences of the molar heat capacities of (▲) 2-methyl-1-butanol, (●) pentan-1-ol**, (■) 2-methyl-2-butanol*, and (  ) pentan-3-ol *** at atmospheric pressure *M. Dzida, P. Góralski, J. Chem. Thermodyn. 41 (2009) **M. Zábranský, V. Růžička and V. Majer, J. Phys. Chem. Ref. Data 19 (1990) 719–762 ***C. A. Cerdeiriña, J. Troncoso, D. González-Salgado, G. García-Miaja, G. Hernández-Segura, D. Bessières, M. Medeiros, L. Romaní and M. Costas, J. Phys. Chem. B 111 (2007) 1119–1128

Isobaric molar heat capacities as function of pressure of 2-methyl-1-butanol at (  ) K and (Δ) K, pentan-1-ol* at (●) K and (○) K, 2-methyl-2-butanol* at (■) K and (□) K, and pentan-3-ol ** at (  ) K and (  ) K (calorimetric measurement) *M. Dzida, J. Chem. Eng. Data (2009) in press **C. A. Cerdeiriña, J. Troncoso, D. González-Salgado, G. García-Miaja, G. Hernández-Segura, D. Bessières, M. Medeiros, L. Romaní and M. Costas, J. Phys. Chem. B 111 (2007) 1119–1128

Isobaric thermal expansion of (▲) 2-methyl-1-butanol, (●) pentan-1-ol*, (■) 2-methyl-2-butanol*, and (  ) pentan-3-ol ** at K *M. Dzida, J. Chem. Eng. Data 54 (2009) **Calculated from densities reported by D. González-Salgado, J. Troncoso, F. Plantier, J. L. Daridon, D. Bessières, J. Chem. Thermodyn. 38 (2006)

Isothermal compressibility of (  ) 2-methyl-1-butanol, (●) pentan-1-ol*, (■) 2-methyl-2-butanol*, and (  ) pentan-3-ol ** at K *M. Dzida, J. Chem. Eng. Data 54 (2009) **D. González-Salgado, J. Troncoso, F. Plantier, J.L. Daridon, D. Bessières, J. Chem. Thermodyn. 38 (2006)

Internal pressure Internal pressure is related to a work of intermolecular forces that accompany the change of volume.

Pressure dependence of internal pressure (●) K; (○) K; (■) K; (□) K; (▲) K; (Δ) K (  ) K; (  ) K; (+) K; () K; (—) K; (-) K pentan-1-ol 2-methyl-2-butanol 2-methyl-1-butanolpentan-3-ol

Summary  The effect of pressure on isobaric heat capacity and isobaric thermal expansion for 2-methyl-1-butanol and pentan-1-ol is smaller than that for 2-methyl-2-butanol and pentan-3-ol and for isothermal compressibility this effect is the highest for 2-methyl-2-butanol Heat capacity, isobaric thermal expansion, and isothermal compressibility  For 2-methyl-1-butanol, pentan-1-ol, and pentan-3-ol the internal pressure as function of pressure shows maximum.  For 2-methyl-2-butanol, the internal pressure increases with increasing pressure. Internal pressure  For 2-methyl-2-butanol, pentan-1-ol, and pentan-3-ol the crossing points of the isotherms of internal pressure are observed.  For 2-methyl-2-butanol, pentan-1-ol, and pentan-3-ol the internal pressure decreases with increasing temperature at pressures up to the crossing point and then it increases with the increase of temperature.  For 2-methyl-1-butanol the internal pressure increases with increasing temperature.