Comment/Reply pubs.acs.org/jced
Cite This: J. Chem. Eng. Data XXXX, XXX, XXX−XXX
Comment on “Density, Sound Speed, and Viscosity of Dihydropyridine Derivatives in Dimethyl Sulfoxide at Different Temperatures” Jian Wang,* Yongqin Du, Anli Xu, and Hongkun Zhao School of Chemistry & Chemical Engineering, YangZhou University, YangZhou, Jiangsu 225002, People’s Republic of China n a recent work published in the Journal of Chemical & Engineering Data, Baluja and Talaviyaare1 reported the volumetric properties of DMSO solutions of dihydropyridine derivatives from 298.15 to 318.15 K at 101.325 kPa. The apparent molar volumes are obtained by eq 1 using the measured mixture densities:
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I
ϕv =
1000·(ρ − ρ0 ) M − mρ ρ
1 kg of binary solvent + (0.00915 × 0.334) kg of solute
−
(1)
1000·(ρ − ρ0 ) M − mρρ0 ρ
here m is the molality (mol·kg ) of the solute in the solution, M is the molar mass (g·mol−1) of the solute, and ρ and ρ0 are the densities (g·cm−3) of the solution and the DMSO, respectively. Thus, the authors decicded to employ the corrected mathematical equation for calculating the apparent molar volume. The calculations are relatively straightforward and involve substituting the experimental values given in Tables 3 and 4 of the published paper by Baluja and Talaviyaare1 into eq 1 above. To demonstrate the problem, we elected to calculate the apparent molar volume at 298.15 K and a VDMP-1 molality of 0.00915 mol·kg−1. The experimental density of the mixture at this temperature and VDMP-1 molality is ρ = 1.096094 g·cm−3, the density of the DMSO solvent at this temperature is ρ = 1.095276 g·cm−3, and the molar mass of VDMP-1 is M = 334 g·mol−1. Substituting the numerical values into eq 1, we obtain
ϕv = 230.25 cm 3·mol−1
(3) (4)
total property of the mixture − total property of the solvent number of moles of solute (5)
That is the total property of the mixture minus the property of the solvent first, and then divide it by the number of moles of solute: © XXXX American Chemical Society
ϕv = 0.000230252 m 3·mol−1
(7)
ϕv = 230.252 cm 3·mol−1
(8)
m
ϕv1
ϕv [this work]
m
ϕv1
ϕv [this work]
mol·kg−1
m3·mol−1
cm3·mol−1
mol·kg−1
m3·mol−1
cm3·mol−1
VDMP-1 at 298.15 0.00915 −74.629 0.01834 −85.994 0.03687 −69.310 0.05558 −63.999 0.07449 −61.416 0.09360 −59.456 VDMP-3 at 298.15 0.00915 −103.975 0.01834 −92.272 0.03687 −74.122 0.05558 −68.437 0.07447 −64.885 0.09354 −63.640 VDMP-1 at 308.15 0.00923 −108.891 0.01851 −88.855 0.03721 −74.439 0.05609 −67.774 0.07519 −62.130 0.09447 −61.705 VDMP-3 at 308.15 0.00923 −110.914 0.01850 −103.313
which is significantly different from the numerical value of ϕv = −74.629 m3·mol−1 that Baluja and Talaviya reported in Table 9 of their paper. In standard thermodynamic textbooks,3 the apparent molar quantities are given by ϕv =
(6)
0.00915 mol
Table 1. Apparent Molar Volumes of Dihydropyridine Derivatives in DMSO at Different Temperatures
(2)
1000 × (1.096094 − 1.095276) 334 − 1.096094 0.00915 × 1.096094 × 1.095276
1095.276 kg·m 3
We performed the same calculation for the apparent molar volume of different solute in the DMSO solvent mixture using both eq 2 and eq 5. The evaluated results together with those reported by Baluja and Talaviya1 are tabulated in Table 1.
−1
ϕv =
0.00915 mol 1 kg of binary solvent
If one carefully reads the paper by Dethlefsen and Hvidt,2 one discovers that the authors state that ϕv calculated by eq 1 is wrong. The apparent molar volume of the binary mixture is given by ϕv =
1096.094 kg·m 3
ϕv =
K 230.252 218.801 235.447 240.696 243.226 245.137 K 217.297 228.917 247.008 252.608 256.072 257.218 K 198.725 218.755 233.117 239.714 245.327 245.683 K 213.267 220.768
VDMP-2 at 298.15 0.00915 −76.725 0.01834 −86.358 0.03687 −69.719 0.05558 −64.346 0.07449 −61.518 0.09359 −59.735 VDMP-4 at 298.15 0.00915 −67.700 0.01834 −64.376 0.03688 −52.797 0.05562 −50.322 0.07457 −50.230 0.09371 −50.552 VDMP-2 at 308.15 0.00923 −111.465 0.01851 −90.416 0.03721 −74.783 0.05609 −68.322 0.07519 −62.427 0.09447 −61.860 VDMP-4 at 308.15 0.00924 −73.019 0.01852 −71.587
K 228.153 218.436 235.038 240.348 243.124 244.850 K 222.589 225.868 237.442 239.899 239.971 239.617 K 196.147 217.191 232.772 239.163 245.029 245.527 K 219.994 221.370
Received: April 12, 2018 Accepted: June 26, 2018
A
DOI: 10.1021/acs.jced.8b00286 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
Journal of Chemical & Engineering Data
Comment/Reply
Table 1. continued m
ϕv1
ϕv [this work]
m
ϕv1
ϕv [this work]
mol·kg−1
m3·mol−1
cm3·mol−1
mol·kg−1
m3·mol−1
cm3·mol−1
VDMP-3 at 308.15 0.03717 −82.772 0.05603 −72.708 0.07507 −67.112 0.09429 −64.917 VDMP-1 at 318.15 0.00932 −112.412 0.01868 −92.325 0.03755 −76.011 0.05663 −67.527 0.07590 −63.835 0.09537 −62.011 VDMP-3 at 318.15 0.00932 −114.917 0.01868 −93.066 0.03753 −77.120 0.05656 −72.569 0.07579 −67.126 0.09519 −66.189
K 241.203 251.197 256.712 258.809 K 198.115 218.133 234.391 242.842 246.478 248.242 K 212.329 234.101 249.927 254.360 259.727 260.546
VDMP-4 at 308.15 0.03725 −62.159 0.05620 −53.762 0.07537 −50.099 0.09475 −49.631 VDMP-2 at 318.15 0.00932 −117.33 0.01868 −94.224 0.03755 −76.542 0.05663 −67.973 0.0759 −64.215 0.09537 −62.434 VDMP-4 at 318.15 0.00932 −83.079 0.01870 −69.936 0.03760 −61.627 0.05673 −56.388 0.07608 −52.767 0.09564 −51.473
K 230.792 239.191 242.852 243.304 K 193.192 216.230 233.858 242.394 246.096 247.817 K 212.609 225.781 234.056 239.294 242.908 244.183
It can be found that the difference between our calculated apparent molar volume (ϕv) and those reported by Baluja and Talaviya1 is large.
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AUTHOR INFORMATION
Corresponding Author
*Tel.: +86514 87975568. Fax: +86 514 87975244. E-mail:
[email protected]. ORCID
Jian Wang: 0000-0001-5882-3470 Notes
The authors declare no competing financial interest.
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REFERENCES
(1) Baluja, S.; Talaviya, R. M. Density, sound speed, and viscosity of dihydropyridine derivatives in dimethyl sulfoxide at different temperatures. J. Chem. Eng. Data 2016, 61, 1431−1440. (2) Dethlefsen, C.; Hvidt, A. Densities and derived volume functions of binary mixtures: (an ethylene glycol derivative + water) at 298.15 K. J. Chem. Thermodyn. 1985, 17, 193−199. (3) Lewis, G. N.; Randall, M. Thermodynamics, 2nd ed.; Pitzer, K. S.; Brewer, L., Eds.; McGraw-Hill Book Co., New York, NY, 1961.
B
DOI: 10.1021/acs.jced.8b00286 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
