M.Phil.
Browse
2 results
Search Results
Item Study of the Effects of Electrolytes on the Carbohydrate Solutions with Volumetric and Viscometric Measurements(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh., 2012-11) Alam, Sheikh Ahidul; Motin, Dr. Md. AbdulIn this study, a simple volumetric and viscometric method was used for the analysis of effect of body containing electrolytes such as NaCl and KC1 on the carbohydrates (glucose, sucrose and maltose) solution. The densities and viscosities of NaCl and KCI at different concentration in aqueous and aqueous glucose, aqueous sucrose and aqueous maltose (1% (w/v), 5% (w/v) and 10% (w/v)) solutions have been determined at 298.15, 303.15, 308.15, 313.15, 318.15 and 323.15 K respectively. The studied electrolytes are found to be dissolved readily in aqueous and aqueous carbohydrate (upto 10% (w/v)) solutions. The density of glucose, sucrose and maltose in aqueous solution were found to be order of Maltose > Sucrose > Glucose. The value of density of NaCl and KCI increases with the increasing of molarity of the electrolytes. Densities of electrolytes in aqueous carbohydrate solutions are concentration of electrolyte can be attributed to solute-solvent interaction. The apparent molar volumes, ɸv were obtained from these densities data. The limiting apparent molar volumes, ɸºv and experimental slope, Sv derived from Masson equation have been interpreted in terms of solute- solvent interactions. The sign of --- i.e. second [(∂^2 〖 Ø v 〗^ )/(∂〖 T 〗^2 )]P derivative of limiting apparent molar volume of solutions with respect to temperature at constant pressure which corresponds to structure making or breaking properties of solutes were determined. NaCl in water, 1% (w/v) glucose and 1% (w/v) maltose solution, the value of [(∂^2 〖 Ø v 〗^ )/(∂〖 T 〗^2 )]P were found to be slightly positive suggesting structure making property. In case of sucrose it shows negative value of [(∂^2 〖 Ø v 〗^ )/(∂〖 T 〗^2 )]P for all the electrolytes containing solvent systems indicating structure breaking property. KCI in water and carbohydrate solution, the values of [(∂^2 〖 Ø v 〗^ )/(∂〖 T 〗^2 )]P were found to be negative suggesting structure breaking tendency. The viscosity vs molarity plots for all the electrolytes systems are linear in all the solvent systems with some exceptions. The viscosity, ƞ for all the studied electrolytes are greater in aqueous carbohydrate solvent system than those in water system. The viscosities coefficients A and B were determined from viscosities data on the basis of Jones Dole equation. The coefficient B gives information regarding solute - solvent interaction and shape and size effect on the solvent structure. The coefficient A represents the ion-ion interaction. The B-coefficient for NaCl in aqueous and aqueous glucose, aqueous sucrose and aqueous maltose solutions (1% (w/v)) at all the temperatures are positive. The positive value of the B-coefficient corresponds to the structure making behavior of solutes. The B-coefficient for KC1 in water and carbohydrate solutions (1%, 5% and 10% (w/v)) are negative. The negative value of B-coefficient corresponds to the structure breaking behavior of KCl. The sign of dB/dT corresponds to structure making or breaking properties of solutes, were determined. For NaCl in aqueous and aqueous carbohydrates (1% (w/v)) solutions, the values of dB/dT are negative which corresponds to structure making behavior. For aqueous and aqueous carbohydrate solution (1%, 5% and 10% (w/v)) of KC1, the values of are positive which corresponds structure breaking behavior.The free energy of activation, ΔG≠ for viscous flow was calculated using Nightinagle and Benck equation at the experimental conditions. Activation enthalpy, ΔH≠ and activation entropy, ΔS≠ were calculated using the Eyring equation and other thermodynamic relations. The effects of electrolytes on the structure of water and aqueous carbohydrate solutions were interpreted in terms of apparent molar volumes, viscosities and viscosity coefficients (A and B) values and thermodynamic parameters (ΔG≠, ΔH≠, ΔS≠).Item Physico-Chemical Studies Of Different Solutions Of Electrolytes NH4C1, FeC13 and NiC12) IN Mixed Solvents (Water-DMSO)(Khulna University of Engineering & Technology (KUET), Khulna, Bangladesh., 2008-08) Reza, K. M. Salim; Prof. Dr. Md. Abdul AzizThe volumetric, viscometric and some other related properties of DMSO in aqueous solutions and some electrolytes such as NH4C1, NiC12 and FeCl3 in water, DMSO and mixed solvents have been measured. The apparent molal volumes, and viscosities, of NH4Cl,NiC12 and FeCl3 in water and water-DMSO solutions were studied as a function of concentration at a wide range of temperatures of 288, 293, 298, 303, 308 and 313 K. The apparent molal volumes at infinite dilutions (limiting apparent molal volume) of these values to the zero concentrations which is practically equal to the partial molal volume. Limiting apparent molal volume for all the three electrolytes were determined by extrapolating co electrolytes studied showed higher values in aqueous DMSO solution then those in aqueous solution in the temperature range of 288 K to 313 K. Apparent molal volumes, , is depended upon the electrolyte concentration as well as on the temperature. Apparent molal volumes showed the gradual decrease of volume with concentration except FeCl3 in water and in pure DMSO solution. The value of viscosities increase in molality of the electrolytes except NH4Cl. No significant change of viscosity observed for NH4Cl with increase in molality in aqueous and in 20% aqueous-DMSO solutions. The viscosities, il for all the studied electrolytes are greater in aqueous DMSO solvent system than those in water system alone indicating that electrolytes in aqueous DMSO systems are more structural than those in aqueous system.Viscosity coefficients (A and B) for the above systems were also determined for the Jones Dole equation. B values for NiC12 and FeCl3 were found to be positive that indicate these electrolytes exhibit structure making behavior in water and in water-DMSO solutions. The B value is negative in water and water-DMSO for NH4C1.This indicates that NH4Cl salt behaves as a water structure breaker in aqueous and aqueous DMSO system. The coefficient A represents the solute-solute interactions coupled with size and shape effect of the solute and to some extent solute-solvent interactions. A coefficient was obtained with an irregular variation. The behaviors of three solutes in binary and ternary systems were discussed in terms of the charge, size and hydrogen bonding effect.