Synthesis and Characterization of Cobalt III Coordination Compounds Procedure Compound J 1 Two grams of compound J were dissolved in a solution composed of 3 mL of concentrated ammonia and 35 mL of water in a 250 mL Erlenmeyer flask 2 The solution was heated and stirred for about 10 minutes until the solid completely dissolved 3 A Buchner funnel was used to filter off the precipitate of cobalt oxide that formed 4 The filtrate was cooled in an ice water bath for 15 minutes 5 2 M of HCl was added to the solution slowly while the solution was still in the bath until pH paper was able to show that the solution was neutral This took about 4 mL 6 2 grams of sodium nitrite were dissolved in the solution 7 Then 2 mL of 6M HCl were added to the solution 8 The solution was swirled and placed in an ice bath for 5 minutes 9 A sintered glass crucible was weighed 10 The solution was put in a dry ice isopropyl alcohol bath for 10 minutes Note the solution was watched to ensure it did not freeze 11 The solution was filtered by suction into the already weighed crucible 12 The solution was washed with 25 mL of ice water 13 The solution was dried with 25 mL of ethanol 14 Air suction was continued for 30 minutes 15 Two weighing bottles were weighed and labeled 16 The vast majority of the product was placed in a weigh bottle and stored in a freezer at about 0oC 17 A very small portion was stored in the other weigh bottle at room temperature 18 Any changes in color with time were recorded 1 1 The University of Illinois at Urbana Champaign Department of Chemistry Hayden McNeil 2011 2012 Chemistry 203 205 Lab Manual pg 73 96 Table of Reagents Chemical monochloro pentaammine cobalt III chloride water Ammonia Formula Co NH3 5Cl Cl2 H20 NH3 Molar Mass g mol Density g mL 250 4456 N A 34 0148 43 0458 Irritating to eyes respiratory system and skin 1 18 N A Toxic Can cause 0 89 severe skin burns Cobalt Oxide Hydrochloric acid Co2O3 HCl 165 86 36 46 5 18 1 191 Sodium nitrite NaNO2 68 995 2 168 Carbon Dioxide CO2 44 01 1 6 isopropyl alcohol C3H8O 60 1 0 786 ethanol C2H6O 46 07 0 789 2 2 Hazards The Chemical Database HordeNet The University of Akron Web 21 Feb 2012 http ull chemistry uakron edu erd Toxic to vascular system blood and liver Skin and eye irritant Eye skin and respiratory irritant Inhilation of high concentration can lead to asphyxiation Eye irritant Also lesser irritant from inhalation and ingestion Eye irritant Flammable
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