scholarly journals Apparent molar volumes of sodium arsenate aqueous solution from 283.15 K to 363.15 K at ambient pressure: an experimental and thermodynamic modeling study

2020 ◽  
Vol 92 (10) ◽  
pp. 1673-1682
Author(s):  
Wanjing Cui ◽  
Hongfang Hou ◽  
Jiaojiao Chen ◽  
Yafei Guo ◽  
Lingzong Meng ◽  
...  

AbstractDensities of the sodium arsenate aqueous solution with the molality varied from (0.04165 to 0.37306) mol · kg−1 were determined experimentally at temperature intervals of 5 K from 283.15 K to 363.15 K and ambient pressure using a precise Anton Paar Digital vibrating-tube densimeter. The apparent molar volumes (Vϕ), thermal expansion coefficient (α) and partial molar volume $({\bar V_{\rm{B}}})$ were obtained based on the results of density measurement. The 3D diagram of apparent molar volume against temperature and molality as well as the diagram of thermal expansion coefficient and partial molar volume against molality were plotted, respectively. On the basis of the Pitzer ion-interaction equation of apparent molar volume model, the Pitzer single-salt parameters ($(\beta _{{\rm{M,X}}}^{(0)v},\beta _{{\rm{M,X}}}^{(1)v},{\rm{ }}\beta _{{\rm{M,X}}}^{(2)v}{\rm{ and }}C_{{\rm{M,X}}}^v,MX = N{a_3}As{O_4})$ and their temperature-dependent correlation F(i, p, T) = a1 + a2ln(T/298.15) + a3(T – 298.15) + a4/(620 – T) + a5/(T – 227) (where T is temperature in Kelvin, ai is the correlation coefficient) for Na3AsO4 were obtained on account of the least-squares method. Predictive apparent molar volumes agree well with the experimental values, and those results indicate that the single-salt parameters and their relational coefficients of temperature-dependence for Na3AsO4 obtained are reliable.

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Hongfang Hou ◽  
Wanjing Cui ◽  
Jiaojiao Chen ◽  
Lingzong Meng ◽  
Yafei Guo ◽  
...  

Densities of sodium arsenite (NaAsO2) aqueous solution with the molality varied from 0.19570 to 1.94236 mol·kg−1 at temperature intervals of 5 K from 283.15 to 363.15 K and 101 ± 5 kPa were measured by a precise Anton Paar Digital vibrating-tube densimeter. Apparent molar volumes (VΦ) and thermal expansion coefficient (α) were obtained on the basis of experimental data. The 3D diagram of apparent molar volume against temperature and molality and the diagram of thermal expansion coefficient against molality were generated. According to the Pitzer ion-interaction equation of the apparent molar volume model, the Pitzer single-salt parameters (βM,X0υ, βM,X1υ, βM,X2υ, and CM,Xυ, MX = NaAsO2) and their temperature-dependent correlation F(i, p, T) = a1 + a2ln (T/298.15) + a3(T − 298.15) + a4/(620 − T) + a5/(T − 227) (where T is temperature in Kelvin and ai are the correlation coefficients) for NaAsO2 were obtained for the first time. The predictive apparent molar volumes agree well with the experimental values, and those results indicated that the single-salt parameters and the temperature-dependent formula are reliable.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Qazi Mohammed Omar ◽  
Jean-Noël Jaubert ◽  
Javeed A. Awan

The properties of 3 binary mixtures containing piperazine were investigated in this work. In a first step, the densities for the two binary mixtures (piperazine + methanol) and (piperazine + acetone) were measured in the temperature range of 293.15 to 328.15 K and 293.15 to 323.15 K, respectively, at atmospheric pressure by using a Rudolph research analytical density meter (DDM 2911). The concentration of piperazine in the (piperazine + methanol) mixture was varied from 0.6978 to 14.007 mol/kg, and the concentration of piperazine in the (piperazine + acetone) mixture was varied from 0.3478 to 1.8834 mol/kg. On the other hand, the density data for the (piperazine + water) mixture were taken from the literature in the temperature range of 298.15 to 328.15 K. In a second step, for the 3 investigated systems, the apparent molar volume (Vϕ) and the limiting apparent molar volume (Vϕ0) at infinite dilution were calculated using the Redlich–Mayer equation. The limiting apparent molar volumes (Vϕ0) were used to study the influence of the solute-solvent and solute-solute interactions. The temperature dependency of the apparent molar volumes was used to estimate the apparent molar expansibility, Hepler’s constant ∂2Vϕ0/∂T2P, and isobaric thermal expansion coefficients αP.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Omer El-Amin Ahmed Adam ◽  
Ammar Hani Al-Dujaili ◽  
Akl M. Awwad

Densities of aqueous solutions of Ethylene glycol (EG), diethylene glycol (DEG), and triethylene glycol (TEG) were measured at temperatures from 293.15 to 318.15 K and molalities ranging from 0.0488 to 0.5288 mol·kg−1. Volumes of all investigated solutions at a definite temperature were linearly dependent on the solute molality; from this dependence the partial molar volumes at infinite dilution were determined for all solutes. It was found that the partial molar volumes at infinite dilution V-2,0 were concentration independent and slightly increase with increasing temperature. The partial molar volumes at infinite dilution V-2,0 or the limiting apparent molar volumes of ethylene glycols were fitted to a linear equation with the number of oxyethylene groups (n) in the solute molecule. From this equation a constant contribution of the terminal (OH) and the (CH2CH2O) groups to the volumetric properties was obtained. The thermal expansion coefficient (α1,2) for all investigated solutions was calculated at temperatures from 293.15 to 318.15 K. The thermal expansion coefficients for all solutes increase with increasing temperature and molality. Values of (α1,2) were higher than the value of the thermal expansion coefficient of the pure water.


1975 ◽  
Vol 28 (10) ◽  
pp. 2109 ◽  
Author(s):  
RH Stokes

The apparent molar volumes of aqueous ammonia, ammonium chloride, aniline and anilinium chloride are measured up to 2 mol l-1 at 25�C by a combination of pyknometric and dilatometric methods. The apparent molar volume f�V of undissociated ammonia at infinite dilution is found to be 24.85�0.02 cm3 mol-1, and that of NH4Cl is 35.71�0.02 cm3 mol-1. The volume change on ionization for the standard states ΔV� is -29.07�0.04 cm3 mol-1. For aniline the values are: f�V(PhNH2) 89.30, f�V(PhNH3Cl) 102.74 and ΔV� -26.49�0.05 cm3 mol-1.


Author(s):  
Heghine H. Ghazoyan ◽  
Shiraz A. Markaryan

This paper studies volumetric properties of ternary dimethylsulfone-ethanol-water systems. The biomedical and environmental significance for the fundamental investigations of aqueous solution of dimethylsulfone and influences of third component on volumetric behavior of this system arises from several reasons. In the global sulfur cycle dimethylsulfide is converted to dimethylsulfone leading to an annual atmospheric production of some million tones of dimethylsulfone, much of which would be deposited in rain and snow. In addition, dimethylsulfone has been extensively studied from a medical point of view. It was established that dimethylsulfone is contained in small amounts in human blood and urine. Also of interest is that methionine is transformed into dimethylsulfone in living organisms. In this work densities of solution of dimethylsulfone in ethanol-water mixtures with various compositions have been measured over available concentration range. As it is evident from experimental data, the increase in a temperature leads to the reduction of density. The apparent and partial molar volumes of solutions were determined over the 298.15–323.15K temperature range. As it follows from these data, the apparent molar volumes increase with increasing of temperature. The influence of ethanol on the volumetric behavior has been taken into account by changing the apparent molar volume compared with the apparent molar volume of the binary aqueous solutions of DMSO2. It is found also the effect of the amount of ethanol on the volumetric properties of these solutions. It is interesting that the effect of ethanol on the values of apparent molar volumes does not change monotone with increasing in quantity of ethanol in ethanol-water mixture. In dimethylsulfone+(ethanol-water) solutions the partial molar volume of dimethylsulfone increases when quantity of ethanol in ethanol-water mixture more than 0.5 molar fraction. The observed phenomena are explained by the presence of competition of intermolecular interactions. In the DMSO2-ethanol-water system the strongest interaction between ethanol and water molecules leads to the increase in partial molar volumes for DMSO2.For citation:Ghazoyan H.H., Markaryan S.A. Volumetric properties of solutions of dimethylsulfone in ethanol-water mixture at tempe-ratures range of 298.15-323.15 K. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 7. P. 27-33.


1979 ◽  
Vol 32 (4) ◽  
pp. 699 ◽  
Author(s):  
GA Bottomley ◽  
LG Glossop ◽  
WP Staunton

A continuous-dilution dilatometer, of the tilting type, specifically designed for study of the apparent molar volumes of aqueous electrolytes at low concentrations, is described. Results at 298.16 K have been secured for multivalent (� 3, � 4, � 6) univalent electrolytes which demonstrate that the apparent molar volumes vary with c� in approximate conformity with the Debye-Huckel limiting-law slopes. Data are presented for: [Co(en)3] Cl3, K3 [CO(CN)6], [Pt(en)3] Cl4, K4 [Mo(CN)8], [C0{(0H)2Co(en)2}3] (NO3)6,Na6C6(C00)6, K4 [Fe(CN)6] and [Co(en)3] (C1O4)3 Ion pairing is a significant disturbing factor which hinders treatment of the data in terms of extended forms of the Debye-Huckel equation.


1977 ◽  
Vol 30 (6) ◽  
pp. 1375 ◽  
Author(s):  
T Mallanoo ◽  
RH Stokes

Conductances of aqueous sodium fluoride solutions have been measured at 15�, 25� and 45�C to give the limiting mobility of fluoride ion. Apparent molar volumes have been obtained by means of a continuous dilution dilatometer.


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