Chem Lab Report
Synthesis Procedure 1
-1.0 Introduction A Cobalt-Amine-Halide compound is synthesized from cobalt (II) chloride hexahydrate. An orange-tinted solid is produced and is considered to be unknown since the specific ligand amounts are unknown. By determining the percent composition of various elements and compounds in the unknown, its true identity can be predicted. Chloride, ammonia, and cobalt are three examples of percent compositions determined to help narrow the selection of possible unknowns. Titrations using Na2S2O3 and HCl to determine percent cobalt and ammonia, respectively, are used. Silver nitrate is used to precipitate the chloride ions in the unknown, which can be measured to determine the percent composition of chloride in the unknown. The results from these three major analyses helped to draw the conclusion that the unknown is in fact [Co(NH3)6]Cl3.
-2.0 Synthesis/Analysis of Cobalt-Amine-Halide Compund (Procedure 1, pgs 16-7)) A cobalt (III) amine halide compound was prepared by making a solution of cobalt (II) chloride hexahydrate and ammonium chloride (NH4Cl) to liberate the Co (II) in the solution. “Activated” charcoal and ammonia are then added to the solution. The Co (II) is then oxidized to Co (III) using hydrogen peroxide (H2O2). This yields an orange crystalline solid of 8.9379 grams, later found to be [Co(NH3)6]Cl3.
[Co(H2O)6]+2 + 6 NH3 [Co(NH3)6]+2 + 6 H2O
2 [Co(NH3)6]+2 + 2 H+ + H2O2 2 [Co(NH3)6]+3 + 2 H2O
-3.0 Analysis for Percent Halide In The Synthesized Cobalt-Ammonia-Halide Compound (pgs 23-4)
HNO3 is used to acidify the soluble chloride-containing cobalt compound. Silver nitrate is used in excess to precipitate chloride ions (Cl-) as AgCl in an approximately
.2400 grams of the unknown compound. This is done in duplicate and purple-tinted precipitates are placed in Gooch crucibles. The precipitates are suction dried using ethyl alcohol then acetone to
-1.0 Introduction A Cobalt-Amine-Halide compound is synthesized from cobalt (II) chloride hexahydrate. An orange-tinted solid is produced and is considered to be unknown since the specific ligand amounts are unknown. By determining the percent composition of various elements and compounds in the unknown, its true identity can be predicted. Chloride, ammonia, and cobalt are three examples of percent compositions determined to help narrow the selection of possible unknowns. Titrations using Na2S2O3 and HCl to determine percent cobalt and ammonia, respectively, are used. Silver nitrate is used to precipitate the chloride ions in the unknown, which can be measured to determine the percent composition of chloride in the unknown. The results from these three major analyses helped to draw the conclusion that the unknown is in fact [Co(NH3)6]Cl3.
-2.0 Synthesis/Analysis of Cobalt-Amine-Halide Compund (Procedure 1, pgs 16-7)) A cobalt (III) amine halide compound was prepared by making a solution of cobalt (II) chloride hexahydrate and ammonium chloride (NH4Cl) to liberate the Co (II) in the solution. “Activated” charcoal and ammonia are then added to the solution. The Co (II) is then oxidized to Co (III) using hydrogen peroxide (H2O2). This yields an orange crystalline solid of 8.9379 grams, later found to be [Co(NH3)6]Cl3.
[Co(H2O)6]+2 + 6 NH3 [Co(NH3)6]+2 + 6 H2O
2 [Co(NH3)6]+2 + 2 H+ + H2O2 2 [Co(NH3)6]+3 + 2 H2O
-3.0 Analysis for Percent Halide In The Synthesized Cobalt-Ammonia-Halide Compound (pgs 23-4)
HNO3 is used to acidify the soluble chloride-containing cobalt compound. Silver nitrate is used in excess to precipitate chloride ions (Cl-) as AgCl in an approximately
.2400 grams of the unknown compound. This is done in duplicate and purple-tinted precipitates are placed in Gooch crucibles. The precipitates are suction dried using ethyl alcohol then acetone to