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.
The purpose of this lab is to focus on how to make zinc iodide in a different way using compounds instead of elements, which are barium iodide and zinc sulfate. We will see if the reaction between these two compounds will occur and make a prediction by writing a chemical equation. The procedures for this lab are to place a small test tube inside a 50mL beaker and weigh it. Then, using a spatula, add 0.45±0.03 g of zinc sulfate heptahydrate into the small test tube and record the mass. After that, dissolve the sample in 2 mL of deionized water and shake the test tube for 1 to 1 ½ minutes to dissolve the solid.
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.
Materials & Methods Identifying the unknown compound solution (#2314) first required the identification of each individual solution. One drop of each solution was added to five individual wells of a spot plate. Next, three drops of 3M hydrochloric acid (to be referred to from now on as HCl). The spot plate was then cleaned, and the procedure above was recreated two more times, the second test done by adding 3M ammonium hydroxide (NH4OH), and the third by adding 1 drop of dimethylglyoxime (DMG). All color observations were recorded and compared to the known behaviors of the focus metals.
Twenty drops of bromothymol blue was also added to the 150mL beaker. The pH was then obtained using the Vernier pH probe and it read 6.68. The 5mL pipet was then used to transfer 5mL of the green solution to the three 50 mL beakers. A 100mL beaker was obtained and filled with 1.0 M HCl solution and the pipet was used to acquire 1mL of the 1.0 M HCl solution. The 1mL of HCl was then transferred to one of the 50mL beakers turning the color of the solution to yellow.
* 3. 3.0 ppm standard: * 3.00 mL of 10.0 ppm phosphate solution was placed in a 25 mL graduated cylinder and diluted to exactly the 10 mL mark with distilled water then poured into a plastic cup labeled 3. Cylinder was rinsed with distilled water. * * 4. Zero standard: 10 mL of distilled water was poured into a plastic cup labeled 0.
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.
3 pipettes 3. 8 test tubes Procedures 1 Take two beakers, one filled with KI and the other with Pb. 2. Take one pipette and fill each test tube with different amounts of KI 3. Take one pipette and fill each test tube with different amounts of Pb 4.
Each flask was labeled according to its content (i.e. ammonium persulfate, potassium nitrate, starch, etc.) 5. The 100 mL flasks were labeled A and B. 6.
Record the actual mass (1.01 grams weighed) in the results table. 2. Transfer the sample of NaOH to the 250 ml volumetric flask. 3. Put approximately 50 ml of deionized water into the flask and dissolve all of the NaOH.