Cobalt(II) Oxygen adduct complex
Inorganic 461 lab
2-29-2012
Abstract
This experiment uses Co(salen) as a model compound illustrating the uptake of oxygen in hemoglobin. SalenH2 was prepared as the intermediate, and reacted with hydrated cobalt to prepare Co(salen). Using Co(salen) the oxygen up-take was tested. The synthesis of SalenH2 produced 0.65 g. The percent yield of salenH2 was 116% on the filter paper and 105% after transferring salenH2 to a vial. The melting point of salenH2, was 128 oC. The color of salenH2 was yellow. This was all expected from salenH2. The synthesis of Co(salen) produced 0.232 g. The percent yield of Co(salen) was 88.22% on the filter paper and 86.1 % after transferring the Co(salen) to a vial. Co(salen)
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A pressure equalizer addition funnel, water condenser fitted with a T joint and an oil bubbler was all added to the system( fig 2). The 25-mL Erlenmeyer flask was placed on top of a sand bath which was heat from a hot plate. Next 12-mL of 95 % ethanol was added through the funnel. The mixture was stirred and flushed with N2. A steady flow of N2 was maintained though the heating processes. A new solution containing, 200 mg cobalt tetrahydrate, 1.5-mL of DI water, was placed into a 10-mL breaker. This solution was added drop wise through the addition funnel to the salenH2 solution in the flask. The system was heated for 1 hr while stirred. The flask was than placed into cold water. Co(salen) was isolated by suction filtration using a Hirsh funnel. The Co(salen) was washed with 10 drops of 95 % ethanol. The product was weighted and placed in a vial the was placed into an desiccators. Till the following week for part C, determination of oxygen absorption by Co(salen). Determination of Oxygen Absorption by Co(salen) At the bottom of a 2x 18 cm side arm test tube, 63.8 mg of Co(salen) was added. Than using a graduated cylinder, 5 mL of DMSO was placed into a 25 mL breaker. Oxygen was pushed thought the apparatus, the test tube with Co(salen) was slightly shaken to expose all of the compound. The displace water lever was taken.
Results and data
This section will explain any data that was collect
1.5mL of phosphoric acid including 3-4 boiling chips were also added to the 25mL flask. The short path distillation apparatus was set up as shown in Figure 1. A heating mantle was used to heat up the 25mL flask. The solution was distilled to the receiving flask until a small amount of liquid remained in the initial RBF flask. At this point the presence of thick grey smoke pulling over into the entire apparatus was observed. The apparatus was then left to cool down. Through the use of pasture pipette, the aqueous layer from the distilled solution was drawn out. Sodium carbonate was then added to the remaining organic solution in order to check the pH and to verify the basicity of the solution. The aqueous layer was again drawn out from the solution. Next, 0.5g of sodium sulfate was added to the remaining organic layer and was swirled until the liquid appeared to be dry and clear. The alkenes were transferred into a clean 10mL flaks using another clean pasture pipe. The apparatus from the first distillation was rinsed off with
Procedure: Filled each test tube with substances provided and subjected them to various conditions. These conditions included, heat, cold water, hot water, acid and basic additions and tested on litmus paper. The reactions were observed and documented at each step.
The crude product was washed by taking the reaction product in the separatory funnel and adding 23 mL of deionized H2O. The mixture was shaken and allowed to settle until layers were observable. The top layer was the desired product and approximately 25 mL of aqueous layer was extracted from the separatory funnel. Next, 25 mL of 5% NaHCO3 was added to the separatory funnel in order to neutralize the acid. This mixture was swirled, plugged with the stopper and inverted. Built-up gas was released by turning the stopcock to its opened and closed positions, releasing CO2 by-product. This was done four times in one minute intervals. The solution was allowed to settle until layers were observable. The bottom layer that contained salt, base and water was extracted from the separatory funnel. The crude product was washed again as mentioned previously.
The powdered cobalt oxalate hydrate was weighed to about 0.3 g and placed in a pre-weighed crucible. The crucible and the cobalt oxalate were then heated until the cobalt oxalate decomposed into a stable, black solid, or Co3O4. Once the crucible was sufficiently
Working in the hood or a designated work area, add about 1 mL of ethyl alcohol to a clean evaporating dish. Place the evaporating dish on a heat- resistant pad.
a. P) Carbon monoxide molecules happen to be just the right size and shape, and happen to have just the right chemical properties, to fit neatly into cavities within hemoglobin molecules in blood that are normally reserved for oxygen molecules.
The purpose of this experiment is to find out if we can identify an unknown Cobalt (II) nitrate concentration by using Calorimetry. Calorimetry involves the use of light to determine a specific solute in solution (Sullivan 238).A given molecule absorbs particular frequencies of light and passes others. If we are able to determine the degree in which various frequencies are absorbed, the population or concentration of a given molecule in solution can be determined. In this experiment we are trying to find out the visible spectrum of the known Cobalt (II) nitrate solution by using absorption versus the wavelengths to determine the analytical wavelength. Once the analytical wavelength is found we can use that to identify the unknown Cobalt (II) nitrate solution, by using the Beer’s law.
Seven test tubes were labeled numerically with 2 mL of VO3- and H2SO42- added to each tube. A small pea size portion of solid Na2SO3 was added to the first test tube. Then, 20 drops of distilled water were added to the second test tube. In the third test tube, 20 drops of (.2 M) NaBr were added. Then, to drops of (.2 M) NaNO2 were added into the fourth test tube. A small portion of Fe(NH4)2(SO4)2 * 6H2O was added into the fifth test tube. The sixth test tube had 20 drops of (.2 M) H2Cr2O4 added, where the seventh test tube was the control tube with no additional chemicals added. All the test tubes were left to react for 3 minutes and then heated in a heated bath for approximately 20 minutes.
First, the students set up a separatory funnel on a support ring over a 150mL beaker labeled carboxylic acid. 2. They then added 25mL of a premixed solution containing acetanilide and tert-butyl methyl ether to the separatory funnel and mixed the solution with 10mL of sodium bicarbonate. The gaseous emission was carefully released while mixing. 3.
Three grams of a mixture containing Benzoic Acid and Naphthalene was obtained and placed in 100 ml beaker and added 30 ml of ethyl acetate for dissolving the mixture. A small amount (1-2 drops) of this mixture was separated into a test tube. This test tube was covered and labelled as “M” (mixture). This was set to the side and used the following week for the second part of lab. The content in the beaker was then transferred into separatory funnel. 10 ml of 1 M NaOH added to the content and placed the stopper in the funnel. In the hood separatory funnel was gently shaken for approximately one minute and vent the air out for five seconds. We repeated the same process in the same manner one more time by adding 10ml of 1M NaOH.
The experiment first started by the calculation of the net oxygen production under white light, it started by putting the Elodea in a volumeter tube containing 3% sodium bicarbonate solution, which was assembled to the volumeter by covering the tube with the plug/pipet/syringe assembly (a 1-2cm air space between the bicarbonate solution and the top rubber cover of the volumeter tube should be left.) Then, clamp the volumeter onto the clamp stand using the tube clamp and fill 2000ml beaker with cold tap water. The beaker should be placed on the clamp stand between the volumeter tube and the light lamp. A five minutes stabilization
The soda ash form experiment 3 was obtained. A 250 ml beaker was obtained and rinsed.
A 0.5 g of sodium tungstate dihydrate was weighed and transferred into a 50-mL round-bottom flask with a magnetic stir bar. Approximately 0.6mL of Aliquat 336 was then transferred carefully into the round bottom flask using a 1mL syringe. The round bottom flask and its contents were then set up in an oil bath. 11mL of 30% hydrogen peroxide and 0.37 g of potassium bisulphate were added to the reaction mixture in the round bottom flask and stirred using a magnetic stirrer. Lastly, 2.5mL of cyclohexene was added using automatic dispenser and the mixture stirred. A condenser was fitted on the round bottom flask, clamped and attached to water horses. The reaction mixture was then heated on the oil bath and the reflux process initiated for an hour while stirring the mixture vigorously. Half way while rinsing, any trapped cyclohexene in the condenser was rinsed. After 1 hour, the round bottom flask was rinsed
14 mL of 9 M H2SO4 was added to the separatory funnel and the mixture was shaken. The layers were given a small amount of time to separate. The remaining n-butyl alcohol was extracted by the H2SO4 solution therefore, there was only one organic top layer. The lower aqueous layer was drained and discarded. 14 mL of H2O was added to the separatory funnel. A stopper was placed on the separatory funnel and it was shaken while being vented occasionally. The layers separated and the lower layer which contained the n-butyl bromide was drained into a smaller beaker. The aqueous layer was then discarded after ensuring that the correct layer had been saved by completing the "water drop test" (adding a drop of water to the drained liquid and if the water dissolves, it confirms that it is an aqueous layer). The alkyl halide was then returned to the separatory funnel. 14 mL of saturated aqeous sodium bicarbonate was added a little at a time while the separatory funnel was being swirled. A stopper was placed on the funnel and it was shaken for 1 minute while being vented frequently to relieve any pressure that was being produced. The lower alkyl halide layer was drained into a dry Erlenmeyer flask and 1.0 g of anhydrous calcium chloride was added to dry the solution. A stopper was placed on the Erlenmeyer flask and the contents were swirled until the liquid was clear. For the distillation
Haemoglobin is a protein molecule found in red blood cells (RBC). Its role in the body is to transport oxygen from the lungs to the body 's tissues and then returns carbon dioxide from the tissues back to the lungs. The transportation of oxygen is only possible when haemoglobin (Hb) within the RBC binds to oxygen. (Martini & Nath, 2006)