In the first part, five 100 mL flasks of 5 mL ligand solution, 5 mL 2 M sodium acetate, 4 mL 3 M NH2OH, and 1-5 mL Fe2+ solution are diluted with water. The absorption spectrum for varying concentrations of Fe2+ are measured using a spectrophotometer and the data is graphed in Excel. The slope of the line is ε in the Beer-Lambart equation A = εcl. In the second part of the experiment, eleven flasks containing diluted stock solutions of Fe2+ and ligand are mixed with 5 mL 2 M sodium acetate and 4 mL 3 M NH2OH and diluted with water. The absorption spectrum is measured using a spectrophotometer and the data is graphed in Excel.
BACKGROUND: For these experiments a 96-well plate was used. Each chemical listed would be put into their own well of 2 drops of each chemical unless instructed otherwise. After the chemicals were each dropped into the wells they were stirred with a different toothpick each time (to not cause cross contamination) and then was observed over a white piece of paper and then a black piece of paper. For each reaction I recorded the well number and took detailed notes on the reactions observed. After the first two tests done with BTB I hypothesized that acids would turn BTB yellow and that bases would remain blue.
The first test tube will be control, the second will be substrate and indicator dye, the third will be dilute extract, the fourth will be the same contents as the second, the fifth will be medium concentration of extract, the sixth will be the same contents as the second, and the seventh will be concentrated extract. 3) Add stock solutions to each tube using the corresponding graduated 5 ml pipette or dispensing device. 4) Adjust the spectrometer to zero absorbance at 500nm. Pour contents of test tube 1 into a cuvette. ) Make sure to keep time, read the spectrometer, and record the data.
Procedure: 1. Fill a beaker two-thirds full of water and add approximately 20 drops of IKI. Write down the solution's color and record the mass of the bag. 2. Do an initial Benedict's test on the 15% glucose/1% starch and the beaker solutions for glucose by putting some of the solution and a roughly equal amount of blue Benedict's solution in a test tube, placing the test tube in boiling water for 90 seconds, and observing whether or not the solution changes color from blue.
For every 20 drops of solution you will add 0.1g of zinc to the new test tube. Repeat steps 3 and four until the solution is clear. If there ever exists too little of the solution to get enough drops, add up to 1mL of distilled water to the solution. 4. Once the solution is clear, retrieve at least ten drops of the solution and place them in a new test tube.
Drops from the column were collected from this point on, using 10 collection tubes labeled 1-10. Each tube was used to collect approximately 5 drops of solution from the column in ascending numerical order. 25 microliters of the buffer solution were consistently being added to the column to prevent the column from drying. The 5 drops of solution in each of the clear collection tubes provides a way to observe the color saturation of the separated molecules. Two visible gradients of reddish brown (collection tubes 1-4) and pinkish red (collection tubes 6-9) were collected.
I inserted the digital thermometer into the test tube and took reading every 30 seconds until the readings remained constant. The readings for the distilled water did not change. I then placed the test tube in the beaker’s ice water bath and set the stopwatch at zero. I carefully stirred the water in the test tube with the thermometer and recorded the temperature of the water at 30-second intervals. Data Table 1: Pure Water Time in seconds | Distilled H2O Room Temp | Distilled H2O Ice bath | 0 | 2431o C | 24.3o C | 30 | | 4.8o C | 60 | | 0.7o C | 90 | | -0.4o C | 120 | | -0.8o C | 150 | | -.10o C | 180 | | -.10o C | Data Table 2: Salt Solution Time in seconds | Salt Water Room Temp | Saltwater Ice Bath | 0 | 20.8O C | 14.2o C | 30 | | 3.0o C | 60 | | 0.2o C | 90 |
Experiment 2 Time | Observations | 5 minutes | Bubbled like sugar | Once salt water was added | Turned soapy white and thick | Equation: METHOD 1) Put 2 cm3 of castor oil into a 250 cm3 beaker and add 10 cm3 of 5mol.dm-3 sodium hydroxide from a measuring cylinder. (Take care when measuring this out and adding it to the beaker to avoid any drips and spills.) 2) Heat the mixture gently over a tripod and gauze, STIRRING CONSTANTLY with a glass rod (otherwise the mixture erupts). Allow to simmer (boil gently) for 5 minutes. Steady the beaker using
Treatment consists of diazepam, 10–20 mg intravenously, repeated every 5 minutes as needed until the patient is calm, and correction of fluid and electrolyte abnormalities and hypoglycemia. The total requirement for
NaNO2 (.0217 mol) was added to the solution and was allowed to react for five minutes. 6M HCl was added slowly to the solution, and then allowed to cool for one hour in an ice bath. The reaction was vacuum filtered to a orange color, and washed with water, ethanol, and ether. The product was allowed to dry for five minutes on the funnel. The resulting product was [Co(NH3)5ONO]Cl2 based on the collected data and yield was 1.215g (.00465 mol, 77.19%) Summary of Physical Properties: [Co(NH3)5Cl]Cl2: Bp 278 °C (lit1 = >150°C) IR in cm-1: 3255 (s, N-H