Cylinder was rinsed with distilled water. * * 2. 2.0 ppm standard: 2.00 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 2. Cylinder was rinsed with distilled water. * 3.
Using a measuring cylinder, add 50cm3 of 1.0mol dm-3 sulphuric(VI) acid to the thyme extract in the conical flask. 8. Titrate the solution in the conical flask with the potassium manganate(VII) solution until a pale pink colour persists for 10 seconds. 9. Repeat the titration until there are two titres within 0.1cm3 of each other.
Part C: Density of Sodium Chloride (NaCl) Solution, a sample of NaCl was obtained and measured using a 100mL beaker and a 10mL pipet to determine the concentration of the solution. In order to obtain the appropriate result, a calibration graph and density measurement was used to determine the concentration of the sodium chloride solution. In conclusion, based on the water temperature of 21.8°C in part A’s graduated cylinder experiment obtained, it was determined that the average density was .0973g/mL with a percentage error of 2.5%. When graphed the measurement was equal to Y=0.988x. Part B: The graduated pipet’s average density at 22.3 °C was determined to be 0.9785g/mL with a percentage error of 1.89% shows the graduated pipet to be more accurate and precise.
Using another 125-mL flask, 60-mL of 0.3622 M potassium hydroxide in ethanol was deposited. Both flasks were clamped in a temperature-controlled bath regulated at 50.0˚C. The solutions were then set in the temperature bath for ten minutes to equilibrate. An empty 250-mL Erlenmeyer flask was also clamped in the same water bath. In another flask 50-mL of ice water was deposited with three-drop phenolphthalein.
The carbonate anion test mixes 1 mL of test solution and drops of 6M HCl. The formation of bubbles shows the presence of carbonate (CO32-). The acetate anion test heats 2 mL of the test solution, 1 drop of 18M H2SO4, and 1 mL (100%) ethanol. A fruity smell, using the wafting technique, shows the presence of acetate
The following data were obtained when a sample of barium chloride hydrate was analyzed as described in the Procedure section. Calculate (a) the mass of the hydrate, (b) the mass of water lost during heating, and (c) the percent water in the hydrate. Mass of empty test tube 18.42 g Mass of test tube and hydrate (before heating) 20.75 g Mass of test tube and anhydrous salt (after heating) 20.41 g. Mass of the Hydrate is 2.33g. Loss (H2O) is 0.34g. Percent H2O in Hydrate is equal 0.34/2.33=14.6% 3.
Objectives: The purpose of this lab is to observe the reaction of crystal violet and sodium hydroxide by looking at the relationship between concentration and time elapsed of the crystal violet. CV+ + OH- CVOH To quantitatively observe this reaction of crystal violet, the rate law is used. The rate law tells us that the rate is equal to a rate constant (k) multiplied by the concentration of crystal violet to the power of its reaction order ([CV+]p) and the concentration of hydroxide to the power of its reaction order ([OH-]q). Rate = k[CV+]p[OH-]q To fully understand the rate law, concentrations of the substances must be looked at first. The concentration is measured in molarity.
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.
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. Place another dry test tube in a 50mL beaker and weigh it. Find a bottle of barium iodide and record the name and molar mass. Then, weight out either anhydrous barium iodide or barium iodide dehydrate into this test tube and dissolve is it in 2 mL of deionized water. Pour the contents of one of the test tubes into the other and a reaction should occur and you should see a white precipitate of barium sulfate form.
c. Prepare the solution by dissolving 38.90 grams of ZnI2 with 500 mL of water. d. 0.0125/0.25 = 0.05 L = 50 mL. This produces 0.0125 moles of ZnI2 5. Exercise 5: a. (0.125)(0.1) = 0.0125 moles of solute b. Pour 50 mL of the stock solution to get the number of moles needed.