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.
Find the molarity is essential to numerous amounts of future procedures such as equivalent weigh. The titration of hydrochloric acid was also completed for practice of titrating and basic understanding of the characteristics of the strong acid. In all three titration experiments an indicator was used to illustrate the
Results and Discussion For the first part of the experiment (Part A), five different 100 mL volumetric flasks were each filled with 1,2,3,4 and 5 mL of iron (II) solution. Then 5 mL of YY ligand, were poured to each of the five flasks. Each flask had 5 mL of 2M sodium acetate and 4 mL of 3M NH2OH. Then the whole solution was diluted up to the 100 mL fill mark with distilled water. This was the solution that was used in order to obtain the absorption spectrum for each of the different iron (II) ligand examples different flasks.
Approximately 20 drops of a .04% Bromothymol blue solution was then added to the beaker of the phosphate buffer. Using a clean 5 mL serological pipette, transfer 5 mL of the phosphate buffer and Bromothymol blue solution to each of three clean 150 mL beakers. Next, using the buret for HCl, add 1 mL of HCl to one of the three beakers, then label this beaker “Yellow”. Next use the buret for NaOH and add 1 mL of NaOH to another of the three beakers, and label this beaker “Blue”. Lastly add 1 mL of water using the buret for water to the last beaker, and label this beaker “Green”.
The two unknown solids are weighed to a mass of 0.15g each. The unknown solids are dropped carefully into the corresponding Erlenmeyer flask wit 50mL of distilled water. The solid in the water must be dissolved and afterwards add 10 drops of Bromecresol green to indicate the change of color when the solution has been titrated. The flask should start with a blue tint. HCl is carefully dropped into the Erlenmeyer flasks with the primed pipette until the solution turn to a green tint.
4. Record the pH measurements in your table. 5. Rinse the beaker thoroughly, and pour into it another 25ml of tap water, and add 0.1M NaOH drop by drop, recording the pH changes in exactly the same way as for the 0.1M HCl. 6.
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.
There was a 36% error and Company Q was not in compliance with the law according to their concentration values. In the next exercise I assembled my 100 mL beaker, well, fine pipet, distilled water blue dye #1, white paper, clear tape, and Gatorade blueberry-pomegranate drink. I set the well on the white paper and numbered them 1 through 10. I taped the well down to keep it in place. Then I filled the well starting with well #1 with distilled water using the fine point pipet according to the instructions on the data table in exercise two.
After donning the appropriate safety gear I began by placing 3 separate sets of 10 drops of distilled water into an unused well of the 24 well plate. I added the following chemicals into one of the three sets of distilled water creating three separate chemical mixtures: HCI, Ammonia, and Sodium Hydroxide. I mixed all thoroughly with a toothpick and then sucked the mixtures into separate pipets. These were placed into the 24 well plate for later use. Using the 96 well plate I combined various chemicals together to observe the chemical changes that were created.
To the second, add 10% NaOH dropwise until the pH is 14. (To do this, add a couple of drops of NaOH to the tube; stir thoroughly with a stirring rod; then touch the stirring rod to a piece of pH paper to check your pH.) To the third, add 0.5% sodium bicarbonate solution to pH 9, and to the fourth, add 2% HCl to pH 2. Record your observations on the data sheet. Repeat the above tests using 2% casein solution.