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.
.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.
The tubes were labeled from 0 to 7, tube 7 being the unknown concentrated solution. Another set of 7 tubes were obtained and 2mls of the BCA Kit Working Reagent (WR) were added to them. The WR was made by adding 50 parts of reagent A to 1 part reagent B supplied in the kit. The WR tubes were blue-green in color. Using a transfer pipette, 2 drops of protein solution was added to the corresponding WR tubes.
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.
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.
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.
The temperature was raised to 70 degrees Celsius and 4.419 g of salicylic acid was measured out on a balance and transferred into a 125. mL Erlenmeyer flask. Next, 8.00 mL of acetic anhydride was measured out and poured into the flask containing salicylic acid, ten drops of phosphoric acid was placed inside. The flask was then immersed into the hot water bath for twenty minutes. A vacuum filtration system was set up and the contents of the flask was transferred onto the filter paper. The mass of the filter paper and watch glass was 42.7131 grams.
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.
Diffusion and Osmosis Lab Part 1A: Diffusion Evidence: Table 1: The Color of Different Solutions Before and After Diffusion for 30 Minutes Content | Initial Solution Color | Final Solution Color | Bag15% glucose1%starch | Cloudy white | Very dark purple | BeakerWater + IKI | Golden yellow | Golden yellow | The above table represents the final and initial colors of the solution that was inside of the dialysis tubing and the solution that was in the beaker. A 15% glucose and 1% starch solution was placed inside of the dialysis tubing. The initial color of the solution in the bag was a cloudy white but after 30 minutes of sitting in the beaker of water and IKI the color turned a very dark purple almost black. Inside of the beaker was a water and IKI solution. After sitting for 30minutes this solution stayed the same color.