Thermodynamic Properties of Binary Liquid Mixtures of Furfural with Toluene and Nitro Benzene at Varying Temperatures

Introduction

Pharmaceutical industries have undergone a major transformation in recent years thanks to ultrasonic analysis of binary liquid mixtures. Utilizing ultrasonic technology is a potent method for understanding the molecular interactions of liquid mixtures¹. Complex developments in liquid mixtures have been interpreted as excess thermodynamic properties. These discrepancies were explained as being caused by strong or weak interactions. The thermodynamic and transport characteristics of pure liquid and liquid mixtures can be used to investigate the nature of molecular interactions (either intermolecular or intra molecular) between the mixing liquids as reported by Sekhar et al². Physical properties like density, viscosity, excess volume, isentropic properties, free length, free volume and acoustic impedance are studied to better understand the environment and strength of intermolecular and intra molecular interactions in multi-component liquid mixtures. Engineering process design and operation also heavily reply on the thermodynamic and transport features of liquid mixtures³. For estimating thermodynamic properties, there exist numerous prediction equations. In this study experimental results are used in studying thermodynamic properties of binary liquid mixtures.

The definition of “biomass” includes dedicated energy plants and trees, aquatic plants, animal waste, agricultural food and feed crop residues, timber, wood residues and other waste resource⁴. Furfural is one of the byproducts of the pyrolysis of biomass containing lignocelluloses. It is utilized as a feedstock for the creation of different resins in the pharmaceutical and agrochemical sectors. Furfural is also used or created in the pulp, paper and food sectors as reported by Muhammad et al⁵. Nitrobenzene is a versatile solvent that is commonly used in synthetic and electrochemical research, a crucial raw material in the production of explosives was reported by Uma et al⁶. At 308.15K and 318.15K, the transport and thermodynamic properties of prepared liquids of binary mixtures were investigated over the entire range of compositions⁷. Research of their binary liquid mixtures, which gain increasing significance because it more accurately simulates complex real time molecular interaction, is the main objective of this work. Thus the binary liquid mixtures of furfural + toluene, furfural+ nitrobenzene and toluene + nitro benzene were measured for ultrasonic velocity, viscosity, density and other estimated excess thermodynamic properties at 308.15K and 318.15K.

Experiment method

Chemical: Furfural (SRL), Toluene (Molychem) and Nitrobenzene (ACS) used were of high purity (<99%). Table-1 shows the thermo physical characteristics of the investigated components.

The purity was further confirmed by comparing the measured values of ultrasonic velocity, viscosity, density with report in the literature, which showed a satisfactory agreement and shown in Table 2. Binary liquid mixtures of various compositions were prepared by volume by weight method, by mixing a constant quantity of pure liquid in airtight stopper bottle⁸ of 50ml capability using an analytical balance with a 0.0001g precision. 

Table 1: Material description:

Chemical name	Molecular formula	Molar mass (g.mol-1)	Stated purity (mol %)	CAS Number
Furfural	C5H4O2	96.08	99	98-01-1
Toluene	C7H8	92.14	99.3	108-88-3
Nitrobenzene	C6H5NO2	123.11	99	98-95-3

Table 2: Comparison of experimental Ultrasonic velocity (U), Viscosity (η) and Density (ρ) in pure liquids with journalism value by 308.15 and 318.15K.

LIQUIDS	T(K)	ρ(g cm-3)		η(mPa s-1)		U(ms-1)
		Experimental values	Literature values	Experimental values	Literature values	Experimental values	Literature values
Furfural9, 10	308.15	1.1447	1.1440	1.2616	1.2600	1406.5	1403.77
	318.15	1.1324	1.1330	1.0921	1.0900	1370.5	1367.81
Toluene11	308.15	0.8374	0.8378	0.5087	0.5099	1253.5	1250
	318.15	0.8396	–	0.3824	–	1256	–
Nitrobenzene12	308.15	0.7980	0.7979	2.0081	2.0080	1218	1209
	318.15	1.1780	1.1773	1.2071	1.2061	1418	1412.5

 

Densities of pure liquids and liquid mixtures were measured by specific gravity method with 10mL relative density bottle and weighed with an exactness of ± 0.001 kg m^-3. Viscosities were determined by Oswald viscometer 10mL capability with an accurateness of ± 0.001 cP. From the measured values of density and flow time ‘t’, viscosity ‘η’ was calculated¹². The values of constants were occurred by measuring the flow time with distilled water and pure nitrobenzene as standard liquids. The flow time were measured with electronic stop clock. The ultrasonic velocity values were measured using an ultrasonic interferometer¹³ (Pico, Chennai, India) with a frequency of 2MHz was calibrated using water and nitrobenzene. The overall accuracy in the measurement is ±0.2%. All the measurements were taken at 308.15 and 318.15K with a temperature accuracy of 0.01K using a digital thermostat. A Perkin Elmer spectrum RX1 was used to record the IR spectra (PerkinElmer, inc., Waltham, MA, USA).

Result and discussion

The following standard formulae are used to calculate the thermodynamic properties based on the investigated data.

Density (ρ)

Where ‘w’ is the mass of the liquid or liquid mixtures, ‘w₀’ is the mass of the water, and ‘d₀’ is the density of the water.

Excess Volume(V^E)

“ρ”- density of the liquid mixtures and X₁, M₁ and ρ₁, X₂, M₂ and ρ₂ – mole fraction, molar mass, and density of pure components 1 & 2 respectively¹⁴.

Isentropic Compressibility(K_S)

Where, “U” – speed of sound and “ρ” – density of the liquid mixtures.

Deviation in Isentropic Compressibility(∆K_S)

Where “∆K_S” denotes the mixtures isentropic compressibility, Φ₁,K₁,S₁ and Φ₂, K₂ S₂ denotes the volume fraction and isentropic compressibility of pure components 1 & 2, respectively.

Viscosity (η)

Where “ρ” denotes the density of a pure liquid or a mixture of liquids, “t” denotes the time flow in seconds and A & B characteristic constants at specified temperature.

Excess Viscosity (∆η)

Where, η₁ & η₂ are the corresponding pure component 1 & 2 viscosity values¹⁵.  

Table 3: Binary liquid mixtures of furfural, toluene and nitrobenzene with physical and thermodynamic properties at 308.15 and 318.15K.

308.15K							318.15K
X1	ρ (g cm-3)	η (mPa.s-1)		U (ms-1)	∆VE (cm3mol-1)	∆Ks (Tpa-1)	X1	ρ (g cm-3)		η (mPa.s-1)		U (ms-1)		∆VE (cm3mol-1)		∆Ks (Tpa-1)
Furfural + toluene							Furfural + toluene
0.0000	0.8539		0.5093	1268	0.0000	0.0000	0.0000		0.8407		0.3771		1255		0.0000	0.0000
0.1365	0.8866		0.6374	1304	-0.0928	-33.6016	0.1365		0.8731		0.4868		1286		-0.0784	-31.9250
0.1941	0.9009		0.6893	1318	-0.1296	-44.1411	0.1941		0.8875		0.5354		1298		-0.1119	-42.0773
0.2999	0.9285		0.7815	1341	-0.2020	-57.7428	0.2999		0.9150		0.6220		1318		-0.1879	-55.8189
0.4302	0.9642		0.8895	1365	-0.2730	-65.6184	0.4302		0.9508		0.7235		1339		-0.2557	-64.0679
0.5172	0.9891		0.9580	1378	-0.2879	-65.5631	0.5172		0.9756		0.7880		1349		-0.2684	-64.1010
0.6013	1.0138		1.0198	1387	-0.2718	-61.2051	0.6013		1.0005		0.8453		1356		-0.2572	-59.7283
0.7133	1.0481		1.0973	1397	-0.2171	-50.4220	0.7133		1.0349		0.9183		1362		-0.1974	-48.6961
0.7895	1.0725		1.1468	1401	-0.1670	-40.0863	0.7895		1.0594		0.9669		1365		-0.1466	-38.4659
0.8917	1.1066		1.2098	1405	-0.0927	-22.5566	0.8917		1.0938		1.0282		1366		-0.0783	-21.5308
1.0000	1.1447		1.2685	1406	0.0000	0.0000	1.0000		1.1324		1.0921		1366		0.0000	0.0000
Furfural + nitro benzene							Furfural + nitro benzene
0.0000	1.1863		1.6194	1439	0.0000	0.0000	0.0000		1.1780		1.2071		1418		0.0000	0.0000
0.1247	1.1818		1.5642	1430	0.0228	2.5496	0.1247		1.1731		1.1859		1408		0.0137	2.1643
0.1915	1.1792		1.5361	1426	0.0340	3.8905	0.1915		1.1704		1.1747		1403		0.0230	3.2813
0.2797	1.1758		1.5011	1420	0.0480	5.4050	0.2797		1.1667		1.1603		1396		0.0350	5.0073
0.3983	1.1711		1.4564	1414	0.0613	6.8765	0.3983		1.1615		1.1429		1388		0.0486	6.4193
0.5048	1.1667		1.4187	1410	0.0674	7.0300	0.5048		1.1567		1.1298		1383		0.0558	6.5400
0.5958	1.1629		1.3879	1407	0.0639	6.5103	0.5958		1.1525		1.1199		1379		0.0513	6.0733
0.6835	1.1592		1.3604	1406	0.0536	5.3596	0.6835		1.1485		1.1121		1376		0.0409	4.9573
0.7911	1.1544		1.3274	1404	0.0377	3.6358	0.7911		1.1433		1.1039		1372		0.0251	3.3456
0.8793	1.1504		1.3018	1403	0.0225	2.3018	0.8793		1.1389		1.0983		1369		0.0122	2.0129
1.0000	1.1447		1.2685	1401	0.0000	0.0000	1.0000		1.1324		1.0912		1365		0.0000	0.0000
Toluene + Nitro benzene							Toluene + Nitro benzene
0.0000	1.1863		1.6216	1439	0.0000	0.0000	0.0000		1.1780		1.2071		1418		0.0000	0.0000
0.1379	1.1403		1.5431	1436	-0.1422	-27.0357	0.1379		1.1304		1.1521		1408		-0.1186	-24.4083
0.2540	1.1019		1.4673	1430	-0.2661	-46.2203	0.2540		1.0910		1.1085		1400		-0.2404	-42.6919
0.3655	1.0650		1.3959	1420	-0.3596	-60.2163	0.3655		1.0533		1.0674		1390		-0.3374	-57.2814
0.4608	1.0333		1.3262	1409	-0.4025	-68.8240	0.4608		1.0210		1.0301		1380		-0.3804	-66.1278
0.5797	0.9937		1.2131	1391	-0.4176	-73.8138	0.5797		0.9807		0.9491		1363		-0.3978	-71.6304
0.6612	0.9665		1.1100	1375	-0.3961	-72.2344	0.6612		0.9530		0.8705		1348		-0.3711	-69.9959
0.7477	0.9375		0.9828	1354	-0.3335	-65.0348	0.7477		0.9236		0.7562		1329		-0.3063	-62.3279
0.8382	0.9070		0.8213	1329	-0.2269	-50.2404	0.8382		0.8927		0.6161		1304		-0.1933	-46.4829
0.9234	0.8785		0.6568	1303	-0.1142	-30.1785	0.9234		0.8640		0.4819		1281		-0.0843	-26.8109
1.0000	0.8530		0.5087	1272	0.0000	0.0000	1.0000		0.8385		0.3728		1255		0.0000	0.0000

 

Table 4: Binary liquid mixtures of furfural, toluene and nitrobenzene with thermodynamic parameters at 308.15 and 318.15K.

308.15K					318.15K
∆η(mPa.s)	∆LF(10-10m)	∆VF(10-14 m3mol-1)	∆Z (kgm-3 s-1)	∆π(Pa)	∆η(mPa.s)	∆LF(10-10 m)		∆VF(10-14 m3mol-1)		∆Z(kgm-3 s-1)	∆π(Pa)
Furfural + toluene					Furfural + toluene
0.0000	0.0000	0.0000	0.0000	0.0000	0.0000	0.0000		0.0000		0.0000	0.0000
0.0245	-69.3918	-2.0867	1.3139	-16.7556	0.0121	-65.8607		-2.9049		0.6505	-42.45
0.0326	-91.2414	-2.7789	2.3241	-24.8084	0.0195	-86.8810		-4.2192		1.4168	-51.33
0.0444	-119.3095	-3.0015	4.1727	-38.0188	0.0305	-115.6168		-5.1773		3.4251	-65.79
0.0536	-135.2528	-2.8141	6.5523	-49.1167	0.0388	-132.4920		-5.0490		5.9304	-78.96
0.0561	-134.3648	-2.5303	7.4868	-52.5884	0.0411	-131.6366		-4.5624		6.7039	-83.04
0.0540	-123.8933	-2.1773	6.9154	-54.8138	0.0383	-120.9535		-3.9004		5.9345	-87.40
0.0465	-100.0258	-1.6306	5.4095	-51.6059	0.0312	-95.9066		-2.8593		3.6993	-83.95
0.0382	-78.3005	-1.2233	4.0633	-44.2965	0.0252	-74.1736		-2.0826		2.1980	-71.93
0.0236	-43.0051	-0.6473	1.8829	-24.0848	0.0135	-40.2638		-0.9713		0.5555	-47.06
0.0000	0.0000	0.0000	0.0000	0.0000	0.0000	0.0000		0.0000		0.0000	0.0000
Furfural + nitro benzene					Furfural + nitro benzene
0.0000	0.0000	0.0000	0.0000	0.0000	0.0000	0.0000		0.0000		0.0000	0.0000
-0.0115	4.3217	0.0115	-3.7922	-1.8701	-0.0067	2.2743		0.0077		-2.5937	-183.24
-0.0161	6.8553	0.0157	-5.8448	-2.7514	-0.0102	3.7780		0.0122		-4.0110	-270.70
-0.0202	9.8032	0.0191	-8.1359	-3.7620	-0.0144	6.9153		0.0159		-6.4559	-372.14
-0.0232	12.7522	0.0213	-10.2851	-4.8025	-0.0181	9.3357		0.0194		-8.2624	-478.70
-0.0236	12.7193	0.0227	-10.2038	-5.3640	-0.0188	9.0775		0.0197		-8.0838	-537.57
-0.0224	11.3152	0.0229	-9.1052	-5.4983	-0.0181	7.8316		0.0187		-7.1332	-553.30
-0.0192	8.5729	0.0209	-7.0509	-5.2508	-0.0158	5.3490		0.0157		-5.3099	-530.94
-0.0144	5.0568	0.0173	-4.3512	-4.3523	-0.0115	2.5552		0.0104		-3.0851	-441.46
-0.0090	3.0487	0.0111	-2.6407	-2.9897	-0.0068	1.0952		0.0045		-1.6378	-303.99
0.0000	0.0000	0.0000	0.0000	0.0000	0.0000	0.0000		0.0000		0.0000	0.0000
Toluene + nitro benzene					Toluene + nitro benzene
0.0000	0.0000	0.0000	0.0000	0.0000	0.0000	0.0000	0.0000		0.0000		0.0000
0.0750	-85.8255	-0.9309	16.0737	0.5906	0.0600	-77.8833	-2.3346		6.9317		52.66
0.1284	-146.2334	-1.7002	26.5000	1.1784	0.1134	-135.8125	-4.3140		13.8556		110.57
0.1810	-189.6352	-2.4431	32.4099	1.8984	0.1652	-181.2138	-6.2184		19.9261		179.03
0.2174	-215.3029	-3.0599	35.3079	2.5604	0.2074	-207.8299	-7.8437		23.1242		247.74
0.2367	-228.5513	-3.7575	35.5711	3.2726	0.2257	-222.9055	-9.6586		24.8186		313.77
0.2243	-221.8295	-4.1340	32.9354	3.5144	0.2151	-216.1674	-10.6917		23.1399		336.81
0.1932	-197.6301	-4.3798	27.5709	3.4791	0.1729	-190.8078	-11.2770		18.8687		314.22
0.1326	-150.5973	-4.2016	19.4525	2.8194	0.1083	-140.8855	-10.7332		11.9111		236.66
0.0628	-88.5151	-3.0689	11.6661	1.5761	0.0453	-79.7547	-7.6340		6.7243		120.52
0.0000	0.0000	0.0000	0.0000	0.0000	0.0000	0.0000	0.0000		0.0000		0.0000

 

Table 5: Standard deviation and coefficients of the Redlich – Kister polynomial equation at various temperatures.

T/K	a	b	c	σ
Furfural + Toluene
VE (cm3mol-1)
308.15	-1.1077	-0.0211	0.0607	0.0052
318.15	-1.0365	-1.0365	0.0749	0.0064
η (mPa.s)
308.15	3.7769	0.3818	0.8864	0.0803
318.15	3.0976	0.3608	0.7262	0.0657
∆KS(Tpa-1)
308.15	-256.2960	14.3467	1.4753	0.4308
318.15	-249.5330	13.8062	1.0171	0.2795
∆η(mPa.s)
308.15	-3.7770	0.3818	0.8864	0.0339
318.15	3.0977	0.3608	0.0000	0.0007
∆Z (kg m-3 s-1)
308.15	27.5603	1.1563	-2.8911	0.2467
318.15	23.7754	0.5017	-4.2782	0.3723
∆LF (10-10 m)
308.15	5.3507	0.1338	0.0242	0.8156
318.15	-0.1712	0.2266	-0.4349	0.0106
∆VF  (10-14 m3mol-1)
308.15	1.0478	1.1510	-0.6172	0.9227
318.15	1.8818	1.6216	-0.1046	0.1436
∆π(10-05 Nm-2)
308.15	215.1630	-1.1856	0.3749	0.1808
318.15	-341.1850	-1.2568	-1.5414	0.2334
Furfural + nitro benzene
VE(cm3mol-1)
308.15	0.2603	0.0008	-0.0119	0.0011
318.15	0.2045	0.2045	-0.0544	0.0009
η (mPa.s)
308.15	5.6814	-0.1735	1.4437	0.1278
318.15	4.8017	-1.3069	3.0813	0.0507
∆KS(Tpa-1)
308.15	27.0760	-1.2965	-1.2180	0.0746
318.15	24.7860	-2.8112	0.8736	0.0995
∆η(mPa.s)
308.15	5.6814	-0.1735	1.4438	0.0001
318.15	4.8018	-1.3070	3.0813	0.0002
∆Z (kg m-3 s-1)
308.15	-39.5562	1.2791	2.3476	0.2014
318.15	-30.4981	1.5467	2.3128	0.1832
∆LF (10-10 m)
308.15	0.4894	-0.0150	-0.0358	0.0031
318.15	0.0018	-0.0252	0.0371	0.0003
∆VF  (10-14 m3mol-1)
308.15	0.2177	-0.0006	-0.0491	0.0084
318.15	0.0629	-0.0436	0.0659	0.0058
∆π(10-05 Nm-2)
308.15	-215.3550	-10.3025	-2.1602	0.1470
318.15	-215.6990	-36.1059	32.0132	0.6720
Toluene+ nitro benzene
VE(cm3mol-1)
308.15	-1.6605	-0.0509	0.0586	0.0032
318.15	-1.5761	-1.5761	0.0908	0.0068
η (mPa.s)
308.15	5.1702	-0.5147	1.0276	0.0773
318.15	4.0199	-0.3777	0.7297	0.0526
∆KS(Tpa-1)
308.15	-288.9300	-16.2319	-0.2111	0.6829
318.15	-278.3900	-16.6389	3.6765	0.3346
∆η(mPa.s)
308.15	5.1702	-0.5147	1.0277	0.0019
318.15	4.0200	-0.3777	0.7297	0.0042
∆Z (kg m-3 s-1)
308.15	143.1650	1.3677	-0.0900	0.0438
318.15	95.5696	3.8653	-5.0718	0.3308
∆LF (10-10 m)
308.15	-9.0176	-0.0399	0.0102	0.0158
318.15	0.1733	0.3654	-0.5878	0.0415
∆VF  (10-14 m3mol-1)
308.15	-13.9947	-2.1795	-1.0539	0.1903
318.15	-3.6067	-5.5960	-2.4651	0.3295
∆π(10-04 Nm-2)
308.15	120.0240	16.1399	-1.8502	0.4417
318.15	115.1310	13.9889	-5.0257	0.0602

 

For binary liquid mixtures

From this theoretical values were calculated¹⁶

Using the theoretical values, the relation was used to determine the standard deviation values

Where, the number of data points is N and the number of coefficients is n.

All of the predicted excess parameters were fitted to a polynomial equation of the Redlich -Kister type using¹⁷ the least squares methods to get the adjustment parameters a, b and c.

Figure 1: Excess Volume(VE) relative to the mole fraction(X1)  of furfural at 308.15K &318.15K for the binary liquid mixtures of furfural (FF) with Toluene (T) and Nitro benzene(NB). Click here to View figure

V^E and ∆K_S values of Furfural + Toluene are negative (Fig 1 and 2) and Toluene + Nitro benzene are more negative (Fig1 & 2) across the entire composition range. The methyl (electron-donating) group in toluene releases electron toward the benzene ring mainly due to hyper conjugation and partly due to inductive effect¹⁸. In toluene hyper conjugation overcomes the inductive effect. As a result, the negative charge on the toluene molecules –CH₃ groups is stabilized, allowing the hydrogen atom to have a positive charge. Due to the hyper conjugation nature of the toluene molecule, there may be a contact between the positive charge on the hydrogen atom of the toluene molecule and the negative charge on the O atom of furfural molecule and nitrobenzene molecule in the two liquid mixtures, resulting in a partial H- bond. Two liquid mixtures are excess volume increases the temperature increase. As the temperature increases, molecules gain thermal energy, which affects the breakdown of intermolecular interaction between dissimilar molecules.

Figure 2: Deviation in Isentropic Compressibility (∆KS) relative to the volume fraction(Φ1) of furfural at 308.15K & 318.15K for the binary liquid mixtures of furfural (FF) with Toluene (T) and Nitro benzene(NB). Click here to View figure

V^E and ∆K_S values of Furfural + Nitro benzene are positive (Fig1& 2), indicating reduced interaction across the entire composition range. Observed excess volume may be broken down into physical, chemical and geometrical effects¹⁹. Dispersion forces and non-specific physical interactions make up the majority of physical interaction that contributes positively. Furfural’s oxygen atom deviates from the nitro group’s oxygen atom, involving the forces of Vander Waals in the process. Dispersive forces, which show a weak chemical contact between dissimilar molecules, have been linked in this study to positive excess volume deviations. V^E decreases with temperature increases, showing the interaction increases with temperature increases. The molecules are activated by thermal energy, which also speeds up the connection of molecules that are dissimilar to one another. As a result, interacting molecules have more incredible energy when approaching components at higher temperatures.

Figure 3: Deviation in Viscosity(∆η) relative to the mole fraction(X1) of furfural at 308.15K & 318.15K for the binary liquid mixtures of furfural (FF) with Toluene (T) and Nitro benzene(NB). Click here to View figure

Figure 4: Deviation in Intermolecular Free Length(∆LF) relative to the Mole Fraction(X1)  of furfural at 308.15K & 318.15K for the binary liquid mixtures of furfural (FF) with Toluene (T) and Nitro benzene(NB). Click here to View figure

∆η values of Furfural + Toluene and Toluene + Nitro benzene are positive (Fig 3) and furfural + Nitro benzene are negative (Fig 3) over the entire range of composition. Toluene + nitrobenzene liquid mixtures have a higher intermolecular interaction than furfural + toluene liquid mixtures, as indicated by the positive value²⁰. The negative value of deviates more from ideality, indicating that there is a dispersion forces between furfural and nitrobenzene. The positive values of binary liquid mixtures are greater than furfural + toluene and lower than toluene + nitro benzene. The graph’s values are in the same order as the V^E and ∆K_S values.

Figure 5: Deviation in Acoustic Impedance(∆Z) relative to the mole fraction(X1)  of furfural at 308.15K & 318.15K for the binary liquid mixtures of furfural (FF) with Toluene (T) and Nitro benzene(NB). Click here to View figure

The observed value of ∆L_F, ∆V_F, ∆πreflect the same ideal as obtained above. Due to an increase in the thermal movements of interacting molecules, the nature of interaction for the three liquid mixtures changes as the temperature rises. Dispersion forces between the mixed liquids cause negative values, whereas attractive forces like dipole –dipole interaction. ∆Z be haves in a manner opposed to ∆L_F, the positive and negative deflection of mixtures indicates the degree of association or dissociation between the mixing components²¹. The measured values of ∆η and ∆Z are positive and negative across the whole composition range (Fig.3&5), which both strongly and weakly support the aforementioned concept. The systems interact in the following order: furfural + nitro benzene < furfural +toluene < toluene + nitro benzene.

There is excellent agreement between experimental and anticipated results for the degree polynomial solution. Table 5 displays the outcomes in terms of the parameters a, b, c & σ. The degree polynomial solution produced using V^E, ∆K_S, η, ∆η, ∆Z, ∆L_F, ∆V_F and ∆πwas found to be in good agreement with the Redlich – Kister parameters.

FT-IR Results

Figures 6 to 8 show FTIR results for toluene and nitro benzene in the binary liquid mixtures with furfural in a molar fraction of 0.5.

Figure 6: FT-IR spectra for the following substances: (a) Pure Furfural liquid, (b) equimolar mixture of Furfural + Nitrobenzene, (c) Pure Nitro benzene liquid. Click here to View figure

Figure 7: FT-IR spectra for the following substances: (a) Pure Furfural liquid, (b) equimolar mixture of Furfural + Toluene, (c) Pure Toluene liquid. Click here to View figure

Figure 8: FT-IR spectra for the following substances: (a) Pure Furfural liquid, (b) equimolar mixture of Furfural + Toluene, (c) Pure Toluene liquid. Click here to View figure

Pure furfural molecule shows a peak at 1686.93cm^-1 which is due to the C=O bond, pure nitrobenzene liquid molecule has a peak at 1523.72cm-1 due to the N=O bond, and pure toluene molecule has a peak at 3032.58cm-1 due to the C-H bond, according to FT-IR  study.

Figure 6 shows a peak at 1680.18cm^-1 in equimolar composition of furfural with toluene. The change in frequency and intensity indicates the existence of an intermolecular partial H-bond between hydrogen atom of the toluene molecule and oxygen atom of the furfural. Figure 7 shows a frequency and intensity of the equimolar combination of furfural + nitrobenzene do not change, indicating that dispersion forces exist between –C=O and –N=O. Figure 8 shows a peak at 3078.38 cm^-1 in equimolar composition of toluene with nitro benzene. The alteration in frequency and intensity is evidence that there is a partial H-bond between hydrogen atom of the toluene molecule and oxygen atom of the nitro benzene.

Conclusion

The mixing characteristics of binary liquid mixtures of furfural + toluene, furfural + nitrobenzene, and toluene + nitrobenzene were investigated in the current study. The magnitude of the chemical interactions between the molecules excess volume, deviation in isentropic compressibility, deviation in intermolecular free length, deviation in intermolecular free volume, deviation in internal pressure, deviation in viscosity and deviation in acoustic impedance has been used to interpret their magnitude.

V^E and ΔK_S values are negative of toluene + nitrobenzene shows more interaction than furfural + toluene interaction and V^E and ΔK_S values are positive of furfural + nitrobenzene is the mixing liquids interact less frequently.  The –O atom of furfural deviates from the intermolecular H- bond form between the toluene molecules hydrogen atom, the hydrogen atom toluene molecules from the intermolecular H- bond form between the nitrobenzene molecules oxygen atom and the furfural molecules oxygen atom and the nitro benzene molecule’s oxygen atom consequently, Vander Waals forces are involved. To determine the variable coefficients, the corresponding thermodynamic excess parameters were calculated using the techniques previously mentioned and adapted to the Redlich- Kister polynomial equation. On the basis of experimental and calculated results, the behavior of the liquid mixtures and the deviation from ideality has been examined. An analysis of FT-IR spectroscopy showed the establishment of H-bond between unlike molecules.

Acknowledgement

The authors acknowledge the Management and Principal of St. Joseph’s College, (Autonomous), Tiruchirappalli – 02, for providing the necessary facilities to carry out the research work.

References

1. Sharma,; Rani M,; Maken S. J. Mol. Liq. 2021, 321, 114366
   CrossRef
2. Sekhar M.C,; Mohan T.M,; Krishna T.V.  J. Mol. Liq.2014, 200, 263–272
   CrossRef
3. Sreenivasulu Karlapudi,; Gardas R.L,; Venkateswarlu P,; Sivakumar K. J. Chem. Thermodyn.2013,67, 203–209
   CrossRef
4. Laura Lomba,; Beatriz Giner,; Ma Carmen Lopez. J. Chem. Eng. Data.2014, 59(2),329-338
   CrossRef
5. Muhammad Saad Qureshi,; Pavel Vrbka,; Vladimír Dohnal. Fuel.2017,191, 518-527
   CrossRef
6. Uma Sivakami K,; Vaideeswaran S,; and Rosevenis A. J. Environ. Nanotechnol. 2018, 7( 3), 22
7. Bolloju Satheesh,; Jagadeesh Kumar Ega,; Kavitha Siddoju,; Siddhartha Marupati,;  Tangeda Savitha Jyostna. chem. data collect.2022,37 , 100812
   CrossRef
8. Felixa S,; Sivakami U.; and R. Venis. World J. Pharm. Pharm. Sci. 2016, 5,1602
   CrossRef
9. Ubagaramary D,; Muthu Vijayan Enoch,; and Kesavaswamy. Orient. J. Chem. 2016 32(1),321-330
   CrossRef
10. Reddicherla Umapathi,; Narasimha Rao C,; Paramespri Naidoo. J.Chem.Thermodyn. 2020,149,106150
    CrossRef
11. Narendra K,; Sudhamsa B,; Sarath Babu M. J. Appl Sol Chem Mod. 2015, 4,119–127
    CrossRef
12. Laura Lomba,; Beatriz Giner,; Isabel Bandres. Green Chem. 2011, 13, 2062-2070
    CrossRef
13. Revathi U,; Rose Venis A. JETIR. 2019, 4, 6
14. Umasivakami K,; Vaideeswaran S,; and Rose Venis A. J. Serb. Chem. Soc. 2018, 83(10), 1131–1142
    CrossRef
15. Ramana CH.V.V,; Kiran Kumar A.B.V,; Satya Kumar A. Thermochim.  Acta. 2013, 566, 130–136
    CrossRef
16. Follegatti–Romero L.M,; Sosa F.H.B,; Costa M.C. J. Chem. Thermodyn. 2019,134, 20-30
    CrossRef
17. Bendiaf L,; Bahadur I,; Negadi A. Thermochim Acta. 2015, 599, 13-22
    CrossRef
18. Rajalakshmia R,; Ravikumara S,; Sivakumarb K. J. Chem. Data Coll. 2019, 24,100299
    CrossRef
19. Kumar S,; Jeevanandham P. J. Mol. Liq. 2012, 174,34-41
    CrossRef
20. Prabhu P,; Rose Venis A. Phys. Chem. Liq.2020, 58,529-544
    CrossRef

---

This work is licensed under a Creative Commons Attribution 4.0 International License.