.40g of NaH_2PO_4, and .40g of Na_2HPO_4 was measured into a 150 mL beaker. 50mL of distilled water was then measured in to a graduated cylinder and added to the 150ml solution of NaH_2PO_4 and Na_2HPO_4. 20 drops of the .04% Bromothymol blue solution was then also added to the buffer solution. After adding the 20 drops the tint of the liquid changed to a light green. The Vernier pH probe was calibrated and used to determine the pH of the phosphate buffer solution which was 6.81.
25 ml of diluted unknown acid solution to 100ml beaker by using 25 volumetric pipet. 10ml of deionized water and 3 drops of phenlpthalin indicator the beaker labeled as 3. Potentiometric titration acid solutions 125 ml of NaOH was obtaining in a beaker and 50 ml of NaOH transfer to buret the tip and the meniscus is at below 0 ml. one magnetic stirring bar placed in a beaker contain one of the known solution on a stir. The pH recorded by using pH electrode before adding NaOH.
First, 0.4040 grams of NaH2PO4 and 0.3989 grams of Na2HPO4 were added to a 150 mL beaker, along with 50 mL of distilled water. Next, 20 drops of bromothymol blue were inserted into the solution. The program LoggerPro and a Vernier pH probe were used to calculate the pH. Then, a volumetric flask was used to measure 5 mL of the buffer solution into each of three, separate 50 mL beakers. After rinsing a volumetric pipet with 1.0 M HCl, 1.00 mL of 1.0 M HCl was transferred to one of the three beakers.
5 mL of 6 M HNO3 was added in beaker to react with copper. Secondly, after 10 mL of distilled water was added, 6 M NaOH was added drop wise until the drop of solution turned red litmus paper blue. Thirdly, the solution was heated with 200 degree until reaction occurs. The reaction mixture cooled to room temperature after continued heated for five minutes. Then, 10 mL of distilled water was added to the precipitate.
A flame test was then conducted and the identity of the cation was determined. To determine the anion, the anion had to be separated first from the cation in the unknown compound. To do this, 0.1 grams of the unknown compound and 0.5 grams of sodium carbonate had to be boiled in 5 mL of distilled water. Once the solution boiled for 10 minutes, the precipitate was centrifuged out and the anion solution was left. 0.1 M silver nitrate was added to the anion solution and a precipitate was formed.
Materials and Methods To first create the three distinct solutions, 50mL of phosphate buffer with a pH of 6.84 was poured into a 150mL beaker with 20 drops of 0.04% Bromothymol blue indicator. 5mL of the solution was then added to three separate 50mL beakers. 1mL of HCl was added to one of the three beakers and labeled ‘Yellow’, 1mL of NaOH was added to another and labeled ‘Blue’, and 1mL of distilled water was added to the last beaker and called ‘Green’. The spectrometer was prepared and left to warm up before calibrating it. Taking the three solutions prepared earlier, each was transferred to three separate cuvette while filling the fourth cuvette was filled with distilled water.
The 15 M NH4OH was added drop wise until a color change occurred, or until 20 drops were added. An additional 10 drops of 15 M NH4OH were then added to each solution. Again, 5 centrifuge tubes were labeled for the same 5 cations and 20 drops of each solution were added to the appropriate centrifuge. HCl was also added to a 50 mL beaker. The Nichrome wire loop was dipped in the HCl solution and placed over the Bunsen burner to disinfect it.
After which time, 2.1 mL of 30% hydrogen peroxide was added slowly followed by sodium hydroxide until a pH of 8 was observed. 20 mL of H20 and 10 mL diethyl ether were added to the flask. The contents were separated and the aqueous layer was rinsed with four 10mL portions of ether followed by 15 mL of sodium bicarbonate. The ether layer was dried with granular magnesium sulfate and then the solvent was removed by evaporation under reduced pressure. Lastly, the final product was analyzed by mass spectrometry and HNMR.
After sitting for 30minutes this solution stayed the same color. Table 2: Solution Colors Before 30 Minutes of Sitting in a Beaker of Water and After Benedict’s test Solution Content | Initial color | Final color | 15% glucose1% starch | Cloudy | Orange | Distilled water | Clear | Blue | This table shows the colors of the solutions before sitting for 30minutes in the solution of water and IKI and the final color after the Benedict’s test has been performed on the solution. The initial color of the 15% glucose and the 1% starch before sitting in the beaker solution for 30 minutes and before the Benedict’s test was perform was a cloudy white color. After the Benedict’s test was performed on this solution it turned an orange color. The solution in the beaker which was distilled water was clear before the IKI was added and before the dialysis tubing was placed in it.
Materials & Methods: First .5 mls of 2000 µg/ml BSA Standard was obtained in a test tube. Then a transfer pipette, 7 plastic tubes were filled with .25 ml of distilled water. Then using a pipette, .25 mls of the BSA from tube 1 and added it to tube 2. Then from tube 2, .25 mls of the solution was added to tube 3. Then from tube 3, .25 mls of the solution was added to tube 4.