American Journal of Engineering Research (AJER) 2016 American Journal of Engineering Research (AJER) e-ISSN: 2320-0847 p-ISSN : 2320-0936 Volume-5, Issue-11, pp-195-200 www.ajer.org Research Paper Open Access www.ajer.org Page 195 Study of molar refraction and polarisability constant of aqueous solutions of NH 4 NO 3 and KBrO 3 at different temperatures. *Arun B. Nikumbh, Meenakshi V. Rathi *P.G. and Research Department of Chemistry, S. S. G. M. College, Kopargaon (M. S.), India-423601. P.G. Department of Chemistry, RNC Arts, JDB Commerce, NSC Science College , Nasik Road, Nasik. Affiliated to S. P. Pune University, Pune (India), 411007. ABSTRACT: Densities and Refractive Indices of aqueous solutions of potassium bromate (KBrO 3 ) and ammonium nitrate (NH 4 NO 3 )have been studied with temperature in the range T= 298.15˚K- 313.15˚K. The data obtained is utilized to determine Specific Refraction (R D ) and Molar Refraction (R M ) of solutions. The values of Refractive indices, Molar Refraction (R M ) and Molar Polarisability (α) constant are found to be decreased with decreasing concentration of solute in solvent and these results are interpreted in terms of various interactions. Keywords: Refractive index, Molar Refraction and Molar Polarisability. I. INTRODUCTION Measurement of refractive index is an essential and important work to study the thermodynamic and other physical properties such as specific refractivity, molar refractivity and polarisability of solutions which provide information about the molecular structure of the components used in the solutions. The molar refractivity reflects arrangements of the electron shells of ions in molecule and yields information about the electronic polarization of ions.The molar refractivity is a measure of the polarisability of the molecule 1 . The study of specific refractivity, molar refractivity and polarisability of salt solutions plays a vital role not only in chemical but also in engineering, medical and biotechnical field. The best part with measurement of refractive index is that it can be measured easily with a high degree of accuracy. Potassium bromate has been widely used in the oxidation of many organic compounds in acidic medium. This oxidation was recognized as friendly to the environment compared to the oxidation carried out by transition metal containing reagents such as chromate, permanganate, cerium and ruthenium salts. Idris S.O. et al. 2 describe the kinetics of the oxidation ofL- Methionine by potassium bromate in hydrochloric acid medium. The kinetics and mechanism of the oxidation of Tartaric acid by potassium bromate in perchloric acidic medium was also studied 3 . A combination of sulfuric acid and potassium bromate in the presence of SiO 2 were used as effective oxidizing agent for the oxidation of alcohol to its corresponding aldehyde and ketone derivatives in various organic solvents with good yield 4 .Potassium bromate as an oxidizing agent in a Titania-based Ru CMP slurry was studied by S. Noyel Victoria 5 . Potassium bromate and Thio-glycolate are the two compounds used worldwide as hair curling solutions. The toxic effect of KBrO 3 on vestibuloocular reflex system of human was studied 6 .Optical dispersion and Molar refractivities of Alkali Halide crystals and aqueous solutions were studied by A.Penzkofer,H.Glas 7 In view of this , the study of density, molar refraction and polarisability constant of KBrO 3 in water and aqueous NH 4 NO 3 solutions is important in industrial and biochemical reactions as oxidizing agent. II. EXPERIMENTAL 2.1 Materials: The chemicals (NH 4 NO 3 and KBrO 3 ) were of high purity(ACS reagent ≥ 99.0%) obtained from Sigma Aldrich,used directly without further purification.Potassium bromate and ammonium nitrateare commercially available in the form of white crystals. Water used for solution preparation was triply distilled with specific conductance of < 10 -6 S .cm -1 .Aqueous solutions of KBrO 3 andNH 4 NO 3 were prepared by dissolving an appropriate amount by weight in appropriate volume of water (w/v).All weighing were done on Contechelectronic balance having accuracy (0.0001g). 2.2 Density measurements:Density measurements were performed using bi-capillary pycnometer. The pycnometer was calibrated by measuring the densities of triple distilled water. The density was measured with an uncertainty of± 1.48× 10 -4 g.cm -3 . The temperatures were measured with an uncertainty of ± 0.01˚K.