Article : Volumetric and viscometric studies on N, N-dimethyl ...

Indian Streams Research Journal 

Vol - I , ISSUE - V [ June 2011 ] : Chemistry 

ISSN:-2230-7850 

<strong>Article</strong> : <strong>Volumetric</strong> <strong>and</strong> <strong>viscometric</strong> <strong>studies</strong> on N, N-dimethyl acetamide <strong>and</strong> 

ethanol binary mixtures at different temperatures 

Author : A.G.Peshwe [ Netaji subhashCh<strong>and</strong>ra bose colleges, N<strong>and</strong>ed ] 

B.R. Arbad [ Dr. Babasaheb Ambedkar Maradwada University, Aurangabad 

] 

Abstract: 

Densities <strong>and</strong> viscosities of binary liquid mixtures of N,N dimethyl acetamide with 

polar solvent viz ethyl alcohol have been measured at 303.15,308.15, 313.15. <strong>and</strong> 

318.15 K .From the density <strong>and</strong> viscosity data the values of various properties viz 

Excess molar volume (V E )Excess viscosity (η E ) <strong>and</strong> Excess Gibb’s free energy of 

activation of flow (∆G E ) have been determined .Further the viscosities of binary 

mixtures have been correlated to various viscosity models. 

On the basis of the values of interaction parameters of theses viscosity models <strong>and</strong> 

also on the basis of the values of various excess properties, the nature of molecular 

interactions between the components of mixtures have been explained. 

Key words: Viscometric <strong>studies</strong>, mixed solvent, binary mixture (nndimetyl 

acetamide <strong>and</strong> ethanol, viscosity models (equations). 

Introduction 

. The thermodynamic <strong>and</strong> transport properties of binary mixtures of N,N- dimethyl 

acetamide with ethanol have been studied, here with, over entire composition 

range, at 303.15,308.15,313.15 <strong>and</strong> 318.15 K . The present study reveals the nature 

<strong>and</strong> extent of interactions between the component molecules in their binary 

mixture. 

In the present paper densities (ρ) <strong>and</strong> viscosities (η) of binary mixtures of N, N 

DMA with ethanol covering the entire composition range (expressed by mole 

fraction x of N, N DMA) at 303.15, 308.15, 313.15 <strong>and</strong> 318.15K are reported



ISSN:-2230-7850 

.From experimental values of densities <strong>and</strong> viscosities excess molar volume (V E ), 

excess viscosity (η E ), excess free energy of activation of viscous flow (∆G E ) of 

ethanol in N, N-DMA have been calculated. These functions offer a convenient 

approach for the study of thermodynamic properties of liquid mixtures. The 

extreme sensitivity of excess functions is due to the size, shape of the molecule <strong>and</strong> 

interaction among themselves <strong>and</strong> gives important information about inter 

molecular forces which are responsible for these interactions . 

The several models (equations) have been used from time to time for 

correlating the viscosity of binary mixtures with those of component liquid 

systems, <strong>and</strong> have been used to test the reliability of the results. 

Experimental: 

N, N-dimethyl acetamide <strong>and</strong> ethyl alcohol were S.D. fine chemicals 

(spectroscopic HPLC, A.R. Grade) & were further purified according to st<strong>and</strong>ard 

procedures 17, 18. The purities were checked by comparing their densities & 

viscosities with in the accuracy ± 1 x 10 -4 gm cm 3 <strong>and</strong> ± 3 x 10 -3 mPas respectively 

<strong>and</strong> given in table no. 1. 

All the binary mixtures were prepared gravimetrically in Stoppard bottles. The 

densities of pure liquid <strong>and</strong> their binary mixture were measured using a single 

capillary pycnometer (made up of Borosil glass) having bulb capacity of 8x 10 - 

3 m 3 . Viscosity of pure liquid <strong>and</strong> their binary mixture was measured using 

Ubbelohde type suspended level viscometer calibrated with tripled distilled water. 

The viscometers containing the test liquid were allowed to st<strong>and</strong> for about 30 min 

in thermostatic bath. The thermostatically controlled water bath whose temperature 

was maintained constant by circulating water through Tulabo F 25 MP thermostat 

(made in Germany) thermostatically controlled water bath, capable of mentioning 

constant temperature (± 0.02 o C). 

Results <strong>and</strong> discussion:



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The experimental values of densities <strong>and</strong> viscosities of pure components have been 

compared with the literature values <strong>and</strong> presented in Table 1.It is found that the 

experimental values compare fairly well with the literature values 1 . 

The excess function is a measure of deviation from the ideal behavior of the 

mixture, <strong>and</strong> found to be highly sensitive towards molecular interactions between 

the component molecules of liquid mixtures. The sign <strong>and</strong> magnitude of these 

excess functions from ideality depends on the strength of interaction between 

unlike molecules. 

1. Excess molar volume (V E ) 

The excess molar volume (V E ) of binary mixture was evaluated from the molar 

volume of mixture (V) <strong>and</strong> that of pure components (V 1 <strong>and</strong> V 2 ) 

Using the following equation 2 . 

V E = V – (x 1 V 1 + x 2 V 2 ) ……………………………………. (1) 

The molar volumes V of the binary liquid mixture were calculated from the 

measured density (ρ) of the mixture using following equation 3 . 

V=(x 1 M 1 +x 2 M 2 ) / ρ ……. (2) 

Where x 1 <strong>and</strong> x 2 are the mole fractions of component 1 <strong>and</strong> 2 of binary liquid 

mixtures respectively, V 1 is M 1 / ρ 1 <strong>and</strong> V 2 is M 2 / ρ 2 . ρ 1 <strong>and</strong> ρ 2 are densities of 

component 1 <strong>and</strong> 2. 

The excess viscosity (η E ) of the given binary liquid mixture was calculated from 

the observed viscosity of mixture <strong>and</strong> that of its pure components using following 

equation 4 , 

η E = η – (x 1 η 1 + x 2 η 2) ……………………………………… (3) 

Where η is viscosity of binary mixture, η 1 <strong>and</strong> η 2 are the viscosities of pure 

component 1 & 2 respectively <strong>and</strong> x 1 <strong>and</strong> x 2 are the mole fraction of the component 

1 & 2 respectively.



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The excess Gibb’s free energy of flow (∆G E ) for the binary liquid mixture was 

computed from the Eyring equation 5 , 

∆G E = RT ( ln η V – x 1 ln η 1V 1 – x 2 ln η 2V 2 ) ----------(4) 

Where the symbols have their usual significance. 

The values of density (ρ), viscosity (η), molar volume (v) <strong>and</strong> excess 

thermodynamic properties viz excess molar volume (V E ), excess viscosity (η E ), 

excess Gibb’s free energy of activation of low (∆G E ) at various temperatures 

303.15, 308.15, 313.15 <strong>and</strong> 318.15K as a function of composition of binary 

mixtures have been presented in Table 2. The result of the study is discussed 

below. 

A perusal of Table 2 shows the values of V E of binary mixture of N, N dimethyl 

acetamide + ethanol are negative over entire range of composition <strong>and</strong> for all 

experimental temperatures. The Fig. 1 exhibits the variation of V E with mole 

fraction x 1 of ethanol at 303.15, 308.15, 313.15 <strong>and</strong> 318.15K. Increases in 

temperature from 303.15 to 318.15K results in decrease in the V E for N, N- 

dimethyl acetamide + ethanol. 

The negative values of V E are due to the chemical or specific interactions which 

can result in decrease in volume <strong>and</strong> these includes possible depolymerisation of 

self associated alcohols by addition of N,N-dimethyl acetamide or formation of 

new bonds (hydrogen bond) between N,N-dimethyl acetamide <strong>and</strong> alcohols <strong>and</strong> 

other complex forming interactions, 

All the values of V E are fitted to Redlich kister type polynomial 6 . 

V E = x 1 x 2 ∑ a 1 ( x 1 – x 2 ) i …………………………………. (5). 

The values of parameter are obtained by least square method <strong>and</strong> are included in 

Table no. 3 

The st<strong>and</strong>ard deviation (σ) calculated as 

σ ( V E ) = [ ( ∑ V E experimental - V E calculated ) / D – N] ½ …………. (6). 

Where D is number of experimental data points <strong>and</strong> N is number of parameters.



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The values of st<strong>and</strong>ard deviation at different temperatures for ethyl alcohol are of 

the order 10 -3 . 

2. Excess Viscosity (η E ) 

A perusal of Table no. 2 shows that the values of η E are positive over entire range 

of composition <strong>and</strong> at all experimental temperatures. 

The negative of η E suggest that dispersion type 7 of forces are predominant in these 

mixtures while positive values may be attributed to the presence of strong 

interactions 8 . 

The plot of η E verses x 1 (mole fraction of alcohol) for the binary mixtures have 

been presented in the Fig. no. 2 

3. Excess Gibb’s free energy activation of flow (∆ G E ). 

The values of ∆ G E for binary mixtures N, N-dimethyl acetamide & alcohol have 

been presented in Table no 2. It is seen the values of ∆ G E are positive over entire 

range of composition for ethanol. 

The values of ∆ G E for above binary mixtures have been plotted against X 1 the 

plots have been represented in Fig. no. 3. The plots are parabolic in shape. 

The negative values of ∆ G E may be attributed to the dominance of dispersion 

forces while positive one to the size effect of the mixing components 9 . According 

to Mayer 10 ∆ G E may be considered. a reliable measure to detect the presence of 

interaction between the molecule, positive values of ∆ G E can be seen in binary 

mixture where specific interactions (hydrogen bonding) between the molecules are 

dominant where as negative ∆ G E indicates characteristic behavior of mixture in 

which dispersion forces are dominant 11 .



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4. Viscosity Models & Interaction parameters: 

The several models (equation) have been put forth for correlating the viscosity of 

binary liquid mixtures with those of component liquid with a view to interpreting 

the molecular interaction in the liquid mixture in terms of interaction parameter of 

the viscosity model. 

1. Grunberg & Nissan 14 have suggested the following logarithmic relation 

between viscosity of the binary liquid mixture & pure components. 

ln η = x 1 ln η 1 + x 2 ln η 2 +x 1 x 2 d 12 ------------(7) 

Where d 12 is constant proportional to interaction energy it is approximate measure 

of strength of the molecular interaction between the mixing components. 

2.Tumara.& kurta 15 developed the following equation for the viscosity 

of binary mixture. 

η = x 1 Φ 1 η 1 + x 2 Φ 2 η 2 + 2(x 1 x 2 Φ 1 Φ 2 ) 0.5 T 12 …………… (8) 

Where T 12 is interaction parameter & depend on temperature &composition of 

mixture. Φ 1 Φ 2 are the volume fraction <strong>and</strong> x 1 x 2 are mole fraction η 1 & η 2 are 

viscosities of pure components 1 & 2 respectively. 

2. Hind et.al 16 suggests the following equation for the viscosity of binary 

mixtures. 

η = x 1 2 η 1 + x 2 2 η 2 + 2 x 1 x 2 H 12 ……………… ……… (9) 

Where x 1 <strong>and</strong> x 2 are the mole fraction, η 1 <strong>and</strong> η 2 are the viscosities of liquid 

component 1 & 2 respectively. η is viscosity of binary mixture & H 12 is Hind 

interaction parameter.



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According to Fort & Moore 4 the value of d 12 (vide equation 7) provide better 

measure of strength of interaction. The variation with composition is large where 

strong specific interaction might be expected, which vary with composition. 

The negative of d 12 indicate the domination of dispersion forces 4 on the other h<strong>and</strong> 

the positive value of d 12 may be attributed to presence of strong interactions. A 

perusal of the value of d 12 shows that these are positive for all binary mixture 

showing strong specific interactions. 

The value of T 12 <strong>and</strong> H 12 21,-,24 ( wide equation 8 &9) for given mixture T 12 & 

H 12 do not show very different variation expect where there is a strong interaction 

between the components. 

A perusal of values of T 12 & H 12 shows that they are positive all the binary 

mixture. Showing strong specific interactions. 

References: 

1. J.Timmer man, “Physico chem. properties of pure organic compounds”, 

Amsterdam 1986. 

2. L Pikka rainen, J.chem.Eng.data, 1983, 28, 381. 

3. D.Papaioannou M. Brida kis & C.G. Panayiotou, J.chem.Eng.data, 1993,38, 

370 

4. R.J.Fort & W.R.Moore, Trans Faraday soc., 1966, 62, 1112 

5. S.Glassstone, K.J.Laider Eyring, The Theory of rate process Mc. Graw Hill , 

Newyork 1941. 

6. O.Redlick <strong>and</strong> A.T.kister, Ind.Eng.chem.1984, 40, 345. 

7. T.M.Aminabhavi & S.S.Joshi, Indian J. Technol, 1992, 30, 187. 

8. M.Ibrahim ,Ph.D. Thesis,Aligarh Muslim University Aligarh,1979.



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9. S.L.Qswal & AvRao, Indian J. chem..sec.A, 1985, 24, 545. 

10. M.Mayer & R. Mayer, J.chem Phys 63, 1971, 143. 

11. B.J.I. Shwara. <strong>and</strong> N.S.varaprasad., Indian J. Pure & Applied Phys, 41, 

2003, 275. 

12. H.Eyring <strong>and</strong> M.S. John., Significant liquid Structure (John Wiley & 

sons, NY, 1969). 

13. H.Eyring, J.chem.Phys, 4, 1936, 65. 

14. L.Grunberg <strong>and</strong> A.H. Nissan, Nature 1949, 164, 799. 

15. M.Tumara <strong>and</strong> M.Kurata, Bult.chem.soc.japan 1952, 25,32. 

16. R.k.Hind , AR Ubbelohde, Trans. Faraday, soc. 1960, 56,328. 

17. A. Vogel., Practical Organic chem.. ,“4 th ” Ed.ELBS, London. 

18. A. Riddick , WB.Bunger Techniques in Chem. organic solvent 12, 4 th ed. 

Wiley Newyork 1986. 

19. . .A.Dean, “Lange’s h<strong>and</strong> book of chem.. 12 th Ed. Mc.Graw Hill , 

NY,1979. 

20. .R.L.David , “CRC H<strong>and</strong> book of chemistry <strong>and</strong> physics.”, 72 th Ed ,CRC 

Press Florida,1992. 

21. R.R.Yadav & V.N.Singh, Indian J. Chem. sec A., 1982,21,17. 

22. R.R.Yadav & V.N.Singh, J. chem. Eng. Data, 1994,39,705. 

23. M.singh & P.c.gupta, J.Chem. Eng. Data, 1995, 40,338. 

24. Dimple Agrawal & Mukther, J.Ind.Chem. Soc., 81, 2004,850. 

25. S.Subha M.S., Ind.J. Chem., 43A, 2004,138. 

26. K.Herris. .& P.Nevitt., J.chem.Eng. Data, 49, 2004, 138. 

27. . Prabhavati C. Shivkumar K., Ind. J. Chem., 43 A 2004, 294.



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28. .J. Nath & A.P. Dixit, J. Chem. Eng. Data, 28, 1983,183. 

29. Ankan. Choudhari, Mousumi Das, J. Ind. Chem. Soc., 82, 2005, 625. 

30. Surabhi Varshney & Mukhatar Singh, J.Ind Chem Soc.83, 2006, 233. 

31. Arti Goyal. Mukhtar singh, J. Ind. chem. soc., 84, 2007, 250. 

32. Shipra Baluja. Nirmal p<strong>and</strong>e, J. Ind. chem. soc., 84, 2007, 1130. 

Table 1: Comparison of experimental density (ρ) <strong>and</strong> viscosity (η) of pure 

liquids with literature values at 303.15, 308.15, 313.15 & 318.15 K 

Liquids Density ( ρ ) gm cm -3 Viscosity ( η ) mPas. 

Ethanol 

303.15k 308.15k 313.15k 318.15k 303.15k 308.15k 313 

0.78112 0.77670 0.76711 0.75911 0.9790 0.8931 0.80 

a) 

0.78121 0.77690 0.76710 0.75102 0.9810 0.9012 0.80 

N,Ndimethyl 

acetamide 

b) 

a) 

0.93210 0.92800 0.92400 0.91912 0.8800 0.8030 0.74 

0.93241 0.92811 0.92412 0.91921 0.8812 0.8031 0.74 

b)



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a =Experimental value 

b=Literature value. 

Table2. :-Densities, viscosities, excess properties <strong>and</strong> interaction parameters 

(d 12, T 12, H 12 ) of binary liquid mixtures of ethanol <strong>and</strong> N-N dimethyl acetamide 

at 303.15, 308.15, 313.15 & 318.15K. 

Sr 

no 

X1 

ρ 

(gm 

cm -3 ) 

η (m 

Pas.) 

η E (m 

Pas.) 

v E (cm 3 mol - 

1 )) 

∆G E (J 

mol -1 ) 

d 12 T 12 H 12 

303.15K 

1. 0.0000 0.93210 0.8800 0.0000 0.0000 0.00 0.00 0.00 0.0000 

2. 0.1737 0.91898 0.9220 0.0248 

- 

0.4441 

68.12 0.1052 0.0248 0.0209 

3. 0.3210 0.90449 0.9487 0.0369 

- 

0.6560 

95.30 0.1254 0.0523 0.0482 

4. 0.5577 0.87313 0.9760 0.0408 

- 

0.6840 

102.27 0.1645 0.0587 0.0616 

5. 0.6591 0.85633 0.9833 0.0380 

- 

0.6040 

89.80 0.1720 0.0463 0.0512 

6. 0.7394 0.84147 0.9848 0.0316 

- 

0.5120 

75.02 0.1956 0.0326 0.0376 

7. 0.8153 0.82583 0.9854 0.0247 

- 

0.3880 

58.37 0.2254 0.0192 0.0229 

8. 0.8832 0.81072 0.9842 0.0168 

- 

0.2730 

36.12 0.2354 0.0087 0.0108



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- 

9. 0.9445 0.79562 0.9812 0.0107 17.14 0.4451 0.0022 0.0028 

0.1290 

10 1.0000 0.78112 0.9790 0.0000 0.0000 0.00 0.0000 0.0000 0.0000 

308.15K 

1. 0.0000 0.92800 0.8030 0.0000 0.0000 0.00 0.0000 0.00 0.0000 

2. 0.1737 0.91466 0.8416 0.0230 

- 

0.4240 

76.21 0.2026 0.0226 0.0191 

3. 0.3210 0.89970 0.8639 0.0320 

- 

0.6020 

106.15 0.1829 0.0475 0.0438 

4. 0.5577 0.86827 0.8909 0.0377 

- 

0.6370 

105.79 0.1717 0.0536 0.0562 

5. 0.6591 0.85164 0.8966 0.0343 

- 

0.5760 

93.70 0.1820 0.0422 0.0467 

6. 0.7394 0.83681 0.8981 0.0286 

- 

0.4880 

75.77 0.2028 0.0297 0.0342 

7. 0.8153 0.82111 0.8998 0.0234 

- 

0.3610 

57.26 0.2400 0.0175 0.0210 

8. 0.8832 0.80597 0.8973 0.0148 

- 

0.2460 

37.85 0.3209 0.0079 0.0098 

9. 

10 

0.9445 0.79108 0.8961 0.0081 - 

0.1180 17.44 0.5571 0.0020 

0.0025 

1.0000 0.77670 0.8931 0.0000 0.0000 0.00 0.0000 0.0000 0.0000 

313.15K 

1. 0.0000 0.92400 0.7470 0.0000 0.0000 0.00 0.00 0.0000 0.0000 

- 

2. 0.1737 0.90951 0.7754 0.0183 79.52 0.3309 0.0203 0.0173 

0.3940 

- 

3. 0.3210 0.89370 0.7906 0.0250 107.23 0.3281 0.0428 0.0396 

0.5640



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4. 0.5577 0.86086 0.8124 0.0331 

- 

0.5940 

110.30 0.3508 0.0492 0.0513 

5. 0.6591 0.84367 0.8156 0.0304 

- 

0.5380 

95.91 0.3894 0.0389 0.0426 

6. 0.7394 0.82846 0.8162 0.0263 

- 

0.4600 

77.75 0.4459 0.0276 0.0313 

7. 0.8153 0.81252 0.8156 0.0213 

- 

0.3510 

60.78 0.5464 0.0163 0.0192 

8. 0.8832 0.79695 0.8125 0.0143 

- 

0.2350 

38.15 0.7493 0.0074 0.0090 

9. 0.9445 0.78165 0.8082 0.0064 

- 

0.1050 

19.77 0.9841 0.0018 0.0023 

10 1.0000 0.76711 0.8050 0.0000 0.0000 0.00 0.0000 0.0000 0.0000 

318.15K 

1. 0.0000 0.91912 0.7080 0.0000 0.0000 0.00 0.0000 0.0000 0.0000 

2. 0.1737 0.90371 0.7391 0.0149 

- 

0.3630 

81.10 0.3949 0.0200 0.0166 

3. 0.3210 0.88735 0.7614 0.0235 

- 

0.5240 

108.88 0.3853 0.0420 0.0384 

4. 0.5577 0.85390 0.7910 0.0310 

- 

0.5660 

115.20 0.4075 0.0471 0.0497 

5. 0.6591 0.83629 0.7986 0.0292 

- 

0.5020 

97.15 0.4494 0.0369 0.0414 

6. 0.7394 0.82086 0.8015 0.0246 

- 

0.4270 

79.25 0.5150 0.0259 0.0304 

7. 0.8153 0.80482 0.8040 0.0200 

- 

0.3300 

61.25 0.6325 0.0152 0.0186 

8. 0.8832 0.78916 0.8029 0.0126 

- 

0.2240 

39.61 0.8748 0.0068 0.0087 

9. 0.9445 0.77371 0.8014 0.0054 

- 

0.0960 

20.10 1.006 0.0017 0.0022 

10 1.0000 0.75911 0.7225 0.0000 0.0000 0.00 0.0000 0.0000 0.0000 

Table 3: Redlich- kister co-efficient of excess molar volume <strong>and</strong> st<strong>and</strong>ard 

deviation for ethanol (1) + N, N-dimethyl acetamide (2) at 303.15, 308.15, 

313.15, <strong>and</strong> 318.15K.



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Temprature A 0 A 1 A 2 σ 

(K) 

303.15 -5.2231 1.3512 0.2868 2.89 x 10 -3 

308.15 -5.1723 1.2912 0.2789 1.11 x 10 -3 

313.15 -4.9783 1.2852 0.2579 6.59 x 10 -3 

318.15 -4.7230 1.2732 0.2472 1.23 x 10 -3 

Table 4 : Redlich- kister co-efficient of excess molar viscosity <strong>and</strong> st<strong>and</strong>ard 

deviation for ethanol (1) + N, N-dimethyl acetamide (2) at 303.15, 308.15, 

313.15, <strong>and</strong> 318.15K. 

Temprature A 0 A 1 A 2 σ 

(K) 

303.15 0.7132 0.1889 -0.0142 2.97 x 10 -3 

308.15 0.6982 0.1779 -0.0572 1.62 x 10 -3 

313.15 0.6851 0.1623 -0.0912 1.53 x 10 -3 

318.15 0.6231 0.1567 -0.0483 1.72 x 10 -3



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Fig 1.Variation of excess molar volumes (V E ) with mole fraction (x 1 ) for 

ethanol (1) + N, N dimethyl acetamide (2) at 303.15, 308.15 , 313.15 <strong>and</strong> 318.15 

K.



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Fig 2. Variation of excess viscosities (η E ) with mole fraction (x 1 ) for ethanol 

(1) + N,N dimethyl acetamide (2) at 303.15,308.15,313.15 <strong>and</strong> 318.15 K.



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Fig 3.Variation of excess Gibb’s free energy of activation of flow (∆G E ) 

with mole fraction (x 1 ) for ethanol (1) + N,N dimethyl acetamide (2) at 

303.15,308.15,313.15 <strong>and</strong> 318.15 K.

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