MICROSCOPE SUPPORTED MEASUREMENT OF EXACT VOLUME OF SOLUTIONS IN PYCNOMETER TO CALCULATE THE DENSITY OF SOLUTIONS

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1 Original Research Article Open Access MICROSCOPE SUPPORTED MEASUREMENT OF EXACT VOLUME OF SOLUTIONS IN PYCNOMETER TO CALCULATE THE DENSITY OF SOLUTIONS *Mohamed Roshan M 1 and Roy Richi Renold G 2 1 Department of Physics, Sadakathullah Appa College, Tirunelveli, Tamil Nadu, India. 2 Research Scholar, M.S. University and Department of Physics, VV College of Engineering, Tisaiyanvillai, Tiruneveli, Tamil Nadu, India. Abstract Knowledge of amino acids interactions in the presence of drugs is necessary to understand several biological processes occurring in living organisms. This interaction study of amino acids requires the measurement of density, ultrasonic speed and viscosity to estimate some important thermodynamic and transport parameters. While measuring the density of solutions using pycnometers, the observation of mass and volume are tedious because both must be observed for every temperature of study when the study is proposed for a range of temperatures. In the present method of density measurement for solutions, the observations of mass and volume are done only once throughout the study for a set of temperatures. The measurement of volume of solution is done with use of pycnometer and standard microscope. This method helps in maintaining the solution at a particular temperature or a set of different temperatures without affecting its thermal equilibrium with the temperature bath throughout the study. Keywords Exact volume of solutions, pycnometer, microscope, volume equivalence to microscope reading INTRODUCTION Volumetric properties of solutes such as the Apparent Volume, partial molar volume, compressibility and expansibility require the accurate measurement of the density values of the respective solutions. Apparent molal volumes (V φ ) of some amino acids have been obtained from precise density measurements by Wadi et al (1990) [1] over the temperature range K and accounted the strength of the solute-solute interactions with the corresponding values of their derivatives. Cibulka et al (2010) [2] reported density data at different temperatures (298 to 443) K and pressures (15 to 17 and 30) MPa for dilute aqueous solutions of glycine and L-alanine and evaluated partial molar volumes at infinite dilution. Partial molar volumes of ten amino acids in water, have been reported from density measurements made at 35⁰C by Iqbal and Ahmed (1993) [3]. Literature survey shows the significance of density measurement in calculating the various properties as reported by several authors. Address Assistant Professor of Physics,SadakathullahAppa College, Rahmath Nagar, Tirunelveli, TamilNadu, India Contact No roshan.shah@yahoo.com With use of Pycnometer the density values of any liquid/solutions can be determined accurately up to the order of g/cm 3. While using the pycnometer for measuring the density, at every temperature, the volume of the liquid/solution and mass of the solution are determined by individual separate attempts at that particular temperature. With the use of whatmann filter papers, volume of the solution is adjusted every time at every different temperature. Then the pycnometer is taken out of the thermal equilibrium for measurement of the mass of the solution. This way of measuring the volume and mass is tedious. A sincere attempt is made to reduce the difficulty in measuring the volume and mass by introducing the use of microscope to calibrate the volume in the pycnometer. Once the Pycnometer is calibrated, then the calibrated standard values can be used to calculate the volume of the liquid /solution and its density. EXPERIMENTAL METHODS AND MEASUREMENTS The Pycnometer is initially filled (mass of empty pycnomter is recorded) with triple distilled water at the basic lower mark. The pycnometer is introduced in the temperature bath at a particular temperature K (25 C). Sai Yaashitha Research Publications 20 Int J Adv Interdis Res.

2 The level of water is adjusted in such a way as to match with basic lower mark (level) using the Whatman filter papers by removing the excess water above the lower mark. When the thermal equilibrium is reached, with the use of Microscope, the meniscus of the water at the lower mark is focused and made to coincide with central crosswire and the respective reading in the vertical scale is noted (figure1). The procedure is repeated for the three successive higher temperatures such as , and K and their corresponding microscope readings are also recorded. Now the pycnometer is removed from the temperature bath and mass of pycnometer with the water is recorded with an accuracy of mg by Shimadzu mass pan. With the known density of water and mass of water, volume of the water at the particular temperature ( ) is calculated. This is taken as the calibrated volume of any solution when the liquid or solution is filled with the basic lower mark at that particular temperature. From these observations (Table1) and density of water from literatures values [4], the pycnometer is calibrated. Figure 1: The meniscus of the water at the lower mark is focused and made to coincide with central crosswire to calculate the base volume of solution. Then, the temperature is set to a higher value at K, after the thermal equilibrium, the crosswire of the microscope is adjusted to new level of the meniscus due to increase in volume of the water. The corresponding reading of the vertical scale is noted (figure 2) for this second temperature. Figure 3: Graph shows the Plot of increase in volume versus increase in microscope reading. The slope of the graph gives the increase in volume for a unit ( 1cm ) increase in microscope reading. The slope of the graph is found to be cm 3 /cm (from figure 3) Calibrated volume at basic lower mark of the pycnometer = cm 3 at K Calibrated volume equivalence per 1 cm of microscope = cm 3 /cm. Calibrated volume equivalence per 0.001cm(L.C) of microscope = cm 3 /cm RESULTS OF THE DENSITY VALUES OF STANDARD LIQUIDS Using this calibrated value (volume equivalence per 1 cm of microscope) volume of the liquid or solution can be calculated from the microscope reading as follows. Figure 2: After the thermal equilibrium for a set temperature, the crosswire of the microscope is adjusted to new level of the meniscus to calculate the increase in volume of solution. Volume of the liquid = ( Microscope reading slope value) + base volume of the liquid which is filled exactly at the lower mark ( Excess liquid is removed with the help of whatmann filter paper as explained earlier). Sai Yaashitha Research Publications 21 Int J Adv Interdis Res.

3 Table 1: Calibration of volume in the Pycnometer using the microscope readings Mass of water G Temperature /K Microscope Readings Cm Literature values of density g/cm 3 Volume Increase in cm 3 volume cm 3 Increase in micro scope readings cm K K (5⁰) (25 c to 30 c) g K (10⁰) (25 c to 35 c) K (15⁰) (25 c to 40 c) K (20⁰) (25 c to 45 c) Table 2: Calculation of Density Values for different liquids and solutions using the calibrated value Mass of Name of the liquid/ liquid/solution solution Acetone g Benzene g Ethanol g 0.02M g Temperature Micro Literature scope Volume of the Density Values readings liquid/solution g/cm 3 g/cm 3 Cm (298.15K) (7) (303.15K) (8) (308.15K) (8) (298.15K) (8) (303.15K) (5) (308.15K) (5) (298.15K) (6) (303.15K) (6) (308.15K) (6) (298.15K) (308.15K) (9) Aniline 0.06M g (298.15K) (308.15K) (9) 0.10M g Paracetamol 0.05M g Metformin Hcl 0.10M g 0.125M g Phenyl Alanine 0.15M g (298.15K) (308.15K) (9) K (10) K (10) K (11) K (12) K (13) (13) K (13) K (13) Sai Yaashitha Research Publications 22 Int J Adv Interdis Res.

4 DISCUSSION For the calibration of the pycnometer, triple distilled water is used and the standard volume up to the base mark in the pycnomter is found to be g/cm 3 (at K).When water is used for the calibration, the volume of the water at higher temperatures (298.15K,303.15K,308.15k,313.15K and K) is determined using the density values from the literature. Using these volumes at different temperatures, the increase in volume of the water at different temperatures with the respect to the base mark/volume is found. The corresponding readings for the meniscus of the liquid using the microscope were recorded. The increase in volume of the given solution is plotted against the increase in microscope reading. Calibrated volume equivalence per 1 cm of microscope was found to be cm 3 /cm. The density of the triple distilled water was calculated using this calibrated values, and verified with the literature values. At all the temperatures, values match with the accuracy of g/cm 3. Further the verification of density values was extended to liquids like acetone, Benzene & ethanol. Almost in all the liquids the determined values of the selected liquids have well matched with the literature as shown in the results. This method of determining the density proved to be more convenient and accurate. The reproducibility in the density measurements was within 0.1 kgm 3. CONCLUSIONS In conventional methods of density measurements of liquids the measurement of mass is done exclusively at every particular temperature for which studies are done. Similarly the volume measurements are also done every time a particular temperature is set. To adjust the volume at a particular temperature to a calibrated mark in the pycnometer, the use of standard filter paper is essential and the process is too tedious. In the present method, measurement of mass is done once for a set of temperatures for which studies are made. Similarly the adjustment of volume at a calibrated mark is done only one time in the method described in this paper. Secondly, when the pycnometer is moved out of the thermal bath for the measurement of mass, the solution s temperature is varying in accordance with the surrounding, it will take time to reach the thermal equilibrium again. In the present method of study the solution is always in the thermal bath till the complete observation of mass and volume is done for set of temperatures for which the investigation is planned. REFERENCES [1] Wadi RK, Islam MN and Goyal RK (1990) Equilibrium and transport properties of amino acid solutions: Part 1. Temperature dependence of apparent molar volume in aqueous solutions between 288 and 308K, Indian J. Chem. A 29: [2] Cibulka I, Hnědkovský L and Šedlbauer J (2010) Partial molar volumes of organic solutes in water. XX. Glycine (aq) and L-alanine (aq) at temperatures (298 to 443) K and at pressures up to 30 Mpa, J. Chem. Thermodyn, 42: [3] Iqbal M and Ahmed T (1993) Partial molar volumes and expansibility of some amino acids in water at 35 o C, Indian Journal of Chemistry A, 32: [4] Kell GS (1975) Thermal expansivity and compressibility of liquid water from 0º to 150ºC: Correlations and Tables for atmospheric pressure and saturation reviewed and expressed on 1968 Temperature Scale, J. Chem. Eng. Data, 20: [5] Tejraj M. Aminabhavi and Kamalika Banerjee (1999) Density, Viscosity, Refractive Index, and Speed of Sound in Binary Mixtures of 1-Chloronaphthalene with Benzene, Methylbenzene, 1,4-Dimethylbenzene, 1,3,5-Trimethylbenzene, and Methoxybenzene at (298.15, , and ) K, J. Chem. Eng. Data, 44(3): [6] Tejraj M. Aminabhavi and Virupakshagouda B. Patil (1998) Density, Viscosity, and Speed of Sound in Binary Mixtures of 1-Chloronaphthalene with Methanol, Ethanol, Propan-1-ol, Butan-1-ol, Pentan-1-ol, and Hexan-1-ol in the Temperature Range ( ) K,Journal of Chemical and Engineering Data, 43(4): [7] Thomas KT and Mcallister RA (1957) Densities of Liquid-acetone-water Solutions up to Their Normal Boiling Points. AIChE Journal, 3(2): [8] Tyushin VYa Composition of the Surface Layer in the n-hexane-acetone System. Vestn.Leningr.Univ. (1966) [9] Rajagopal K and Edwin Gladson S (2011) Partial molal volume and partial molal compressibility of four homologous amino acids in aqueous sodium fluoride solutions at different temperatures, Journal of Chemical Thermodynamics, 43: Sai Yaashitha Research Publications 23 Int J Adv Interdis Res.

5 [10] Shekaari H, Zafarani-Moattar MT and Ghaffari F (2016) Volumetric, Acoustic and Conductometric Studies of Acetaminophen in Aqueous Ionic Liquid, 1- Octyl-3-methylimidazolium Bromide at T = K, Phys. Chem. Res. 4(1): [11]Suvarcha Chauhan, Kuldeep singh, Kuldeep kumar (2016) Drug-Amino acid interactions in Aqueous Medium: Volumetric, Compressibility and Viscometric Studies, Journal Chemical Engineering data. 61 (11): [12] Rajagopal K and Jayabalakrishnan SS (2010) Effect of Temperature on volumetric and viscometric properties of Homologous Amino acids in Aqueous solutions of Metformin Hydrochloride, Thermodynamics and Chemical Engineering Data- Chinese journal of Chemical Engineering, 18(3): [13] Anil Kumar Nain, Renu Pal, Neetu (2014) Physico chemical study of solute-solute and solute-solvent interactions of l-phenylalanine in (water+arabinose/glucose/sucrose) solutions at different temperatures, J.Chem.Thermodynamics, 68: Citation: Mohamed Roshan M and Roy Richi Renold G (2017) Microscope supported measurement of exact volume of solutions in pycnometer to calculate the density of solutions, Int J Adv Interdis Res, 4 (3): doi: /ijaidr Received: Aug 19, 2017 Accepted: September 25, 2017 Published: September 30, 2017 License : Mohamed Roshan M and Roy Richi Renold G (2017). This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Sai Yaashitha Research Publications 24 Int J Adv Interdis Res.