IOSR Journal of Applied Physics (IOSR-JAP) e-ISSN: 2278-4861.Volume 9, Issue 4 Ver. I (Jul. – Aug. 2017), PP 64-67 www.iosrjournals.org DOI: 10.9790/4861-0904016467 www.iosrjournals.org 64 | Page Solubility and Density of Silver Iodide in Water and DMF at Various Temperatures as Function of Potassium Iodide. *U P Shinde 1 H S Aher 2 T B Pawar 2 1Dept. of Physics and Electronic Science L. V. H. College, Panchavati, Nashik-422003 Dist- Nashik (M.S.) India 2Dept. of Chemistry L. V. H. College, Panchavati, Nashik-422003 Dist- Nashik (M.S.) India Abstract: The solubility of silver iodide (AgI) in water, dimethyl formamide (DMF), KI + Water, and KI + DMF were measured using an analytical gravimetric method at temperatures ranging from (298.15 to 315.15) K. The densities of the saturated solutions are also reported. The results are interpreted in the form of enthalpy change ∆H. Keywords: Silver iodide, solubility, density, potassium iodide, molar enthalpy, molar entropy, Gibbs energy. I. Introduction AgI used for cloud seeding [1]. Solubility studies of electrolytes have applications in diverse fields such as the pharmaceutical industry, agriculture, biology, medicine, etc [2]. Solubility data for many inorganic salts in aqueous systems are available [3-5]. However there is no data available for solubility of silver iodide in presence of potassium iodide as additive. Therefore we have undertaken measurements of solubility and densities of silver iodide in presence of potassium iodide at various percentage of KI in Water and DMF at various temperatures. The thermodynamic functions of solution of AgI were calculated by using Van’t Hoff equation. II. Materials And Methods The apparatus and procedures used for solubility and density measurement have been described earlier [6-8]. An excess amount of AgI was added to the KI binary solvents mixtures prepared by weight (Shimadzu, Auxzzo) with an uncertainty of ± 0.1 mg, in a specially designed 100 mL double jacketed flask. Water was circulated at constant temperature between the outer and inner walls of the flask. The temperature of the circulating water was controlled by thermostat to within (± 0.1) K. The solution was continuously stirred using a magnetic stirrer for long time (about 1 h) so that equilibrium is assured, no further solute dissolved, and the temperature of solution is same as that of circulating water; the stirrer was switched off; and the solution was allowed to stand for 1 h. Then a fixed quantity of the supernatant liquid was withdrawn from the flask in a weighing bottle with the help of pipet which is hotter than the solution. The weight of this sample was taken and the sample was kept in an oven at 343 K until the whole solvent was evaporated and the residue was completely dry. This was confirmed by weighing two or three times until a constant weight was obtained after keeping the sample in an oven for another 30 min every time. The solubility has been calculated using weight of solute and weight of solution. The saturated mole fraction solubility was calculated using usual equations. Densities were determined using a 15 cm 3 bicapillary pycnometer. For calibration of pycnometer triply distilled and degassed water with a density of 0.99705 g·cm -3 at 298.15 K was used. The pycnometer filled with air bubble free experimental liquids was kept in a transparent walled thermostat (maintained at constant temperature ± 0.1 K) for (10 to 15) min to attain thermal equilibrium. The heights of the liquid levels in the two arms were measured with the help of a traveling microscope, which could read to 0.01 mm. III. Figures And Tables Table 1: Mole fraction solubility (X) of AgI in KI + Water and KI + DMF solvent. AgI+KI-Water Temp ( o K) 1% KI 2% KI 3% KI 4% KI 5% KI 298.15 1.68E-05 2.69E-05 9.44E-05 0.00019 0.00029 303.15 6.61E-05 6.69E-05 0.00011 0.00017 0.00025 308.15 0.00010 8.00E-05 0.00014 0.00023 0.00028 315.15 2.30E-04 6.21E-05 0.00016 0.00022 0.00030 AgI+KI-DMF Temp ( o K) 0.1% KI 0.2% KI 0.3% KI 0.4 KI 0.5% KI 298.15 0.0009 0.00234 0.00264 0.00335 0.00290 303.15 0.0010 0.00237 0.00326 0.00372 0.00353 308.15 0.0011 0.00234 0.00354 0.00388 0.00548 315.15 0.0011 0.00257 0.00352 0.00398 0.00643