Indian Journal of Chemical Technology Vol. 1, March 1994, pp. 93-97 Densities and viscosities of the binary aqueous mixtures of tetrahydrofuran and 1,2-dimethoxyethane at 298, 308 and 318 K Bijan Das. Mahendra Nath Roy & Dilip K Hazra* Department of Chemistry, North Bengal University. Darjeeling 734 430.India Received 10 June 1993: accepted 13 October 1993 The densitiesand viscosities have beendetermined for the binary systems of water with tetrahyd- rofuran and 1,2-dimethoxyethane at 298, 308 and 31~ K. From the experimentalresults,the exces~ molar volumes (VE) and the deviation of viscosity from the mole fraction average(11,,) have been derived. These are explained on the basi~ of molecular interactions betweenthe componentsof the mixtures. There has been a recent upsurge of interest I -I in The kinematic viscosities were measured hy the thermodynamic properties of binary liquid means of a suspended Uhhelohde-type viscometer mixtures. These have been extensively used to oh- with a flow time of water of about 539 s at 298 tain information on the intermolecular interac- K. Temperatur~ control during viscosity measure- tions and geometrical effects in these systems-l. ments was ::I: 0.01 K. The precision of the viscos- We have presented here the densities and viscosit- ity measurements was ::I: 0.05%. The kinematic ies for tetrahydrofuran-water and 1,2-dimethoxy- viscosities (v) were converted into the absolute ethane-water mixtures at 298, 308 and 318 K. viscosities (1]) by multiplying the former with .. density (p). Experimental Procedure The purification of 1,2-dimethoxyethane (Fluka, Results purum) has been described earlier~. The solvent The experimenal results of densities and visco- was shaken well with FeSO~ (A.R., BDH) for 1-2 sities at various mole fractions of organic solvents h, decanted and distilled. The distillate was ref- and at three different temperatures are reported luxed for 12 h and redistilled over metallic sodi- in Table 1. urn. The purified solvent had a density of 861.32 Binary liquid mixture viscosities have heen rep- kgm 1 and a coefficient of viscosity of 0.4236 resented by a number of correlations in terms of mPa s at 298 K which agree well with the report- their pure component properties and interaction ed values". parameters. Grunberg and Nissanx proposed the Tetrahydrofuran (Merck, India) kept several following equation: d~y~ over KOH, ~as refluxed for 24. h and then In" = x I In "1 + x ~ In ,,~+ x I x ~ d ...(I) dlstll~~d ove~ LI.AIH~. The de~slty (880.72 where xland X2are the mole fractions of tetrahyd- kgm .) and vIscosity (0.4630.mPa s) at 298 K of rofuran (or 1,2-dirnethoxyethane) and water re- the ;olvent co~pared well with the rep<?rted ~a- spectively, "I, "II and "I~ are the respective coeffi- lu~s ..All s<;>l~tlons were prepared hy weight with cients of viscosity of the mixture, tetrahydrofuran deionized dl.s~llled water.. (or 1,2-dimethoxyethane) and water, and d is a The densIties were measure~ with an Ostwald- constant proportional to the interaction energy Sprengel type pycn.ometer h~vmg a bulb volu~e and is regarded as a measure of interaction be- of 25 cn1' and an Internal diameter of the capl~- tween the components. The values of d are given lary of about 1 mm. The pycnometer was call- .T bl I brated at 298, 308 and 318 K with doubly dis- In a e . .11d t Th t t t I h d The excess molar volumes have been calculated ., tI e wa er. e empera ure con ro a an ac- h h 4' II .. f + 0 01 K h d .bit. f h Y t e.o owIng equation: curacy 0 -.; t e repro UCI Ity 0 t e dellsitymeasurementwas ::1:3 x 10--'kgm-J. VF= V-(x1 V1+x~ V~) ...(2) where JI; VI and V 2 are the molar volumes of the .Autht' to whom correspondence should be addressed mixture, tetrahydrofuran (or 1,2-dimethoxyethane)