.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.
Then, six capillary tubes were used to spot the five known solutions and the one unknown. The unknown number and the colors of each solution were recorded. The Chromatography paper was then folded into a cylinder and stapled at the top edge. After that, enough 9:1 acetone: 6 M HCl solution was poured into a 600 mL beaker so that the depth was about 0.5 cm and the chromatography paper was stood up in the beaker, which was then covered with foil. The chromatography paper was removed with tongs
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.
Stir each of the systems by drumming with your fingers on the loosely held test tube. To a 6th test tube, add about 1-ml Silver Nitrate solution. Label each test tube with the name of the chemical you used. Record these observations: System 1: FeCL3 System 2: KSCN System 3: K4Fe(CN)6 System 4: AgNO3 7. Mix pairs of solutions in the following ways, and record all of your observations in the data table.
Introduction: This experiment was executed to determine the concentration 7 different solutions with different concentrations. The solution was part water and part Bovine Serum Albumin (BSA). To determine the concentration, a spectrophotometer was used. The use for a spectrophotometer is to determine the concentration of a liquid using light to determine the absorbency. Materials & Methods: First .5 mls of 2000 µg/ml BSA Standard was obtained in a test tube.
About 125 mL of standard HCl with a molarity of 0.3125 and was poured into a buret. An unknown sample of soda ash was obtained, and for each trial, a little over 1 g of the soda ash was quantitatively transferred into a wide mouth Erlenmeyer flask. About 75 mL of DI water and 5 drops of methyl purple indicator was then added to the soda ash powder. The solution was titrated once until the solution turned light purple, and then the flask was put on the hotplate for about 3 minutes of gentle boiling. After, the solution was titrated once more in order to reach the endpoint that was indicated by a bullfrog green color.
This report includes measurements collected from graduated cylinders, balances, and metric rulers, and the densities the data helped calculate. Hypothesis Based on our study of density, we should be able to calculate the mass and volume of each of the seven objects to find their densities and then determine what each of the objects are using the calculated density. Materials and Methods At Lab Station 1, a dry 100mL graduated cylinder was placed on a balance and the mass was recorded in grams to the nearest .01 gram. Approximately 60mL of the Clear Liquid 1 was carefully poured into the graduated cylinder. The graduated cylinder was placed on the scale again (with the added liquid) and the mass was measured in grams to the nearest .01 gram.
These solutions should be in dropper bottles. Also concentrated HCl was be needed. The equipment need for this part of the experiment are 10 centrifuge tubes, a test tube rack, a distilled water bottle, medicine dropper, cobalt glass, Nichrome wire loop, striker, a 50 mL beaker, a stir rod, pipets, and a Bunsen burner. To begin the experiment, 5 centrifuge tubes were labeled for each of the 5 cations, K+, Fe3+, Zn2+, Cu2+ and Co2+. 10 drops of each solution was added to the appropriate centrifuge tube.
Another control consisted of 5cm³-distilled water in fifth test tube and 5cm³ casein in a final test tube. All of these were also placed into the water bath. Black card was placed behind the test tubes to help spot the clearing of the solution. The enzyme and substrate were mixed, a stopwatch started immediately, and the time for the suspension to clear noted. This was repeated for the controls, and the whole experiment repeated for different temperatures, ranging from 25°C - 65°C.
A 5 mL pipet was rinsed with the buffer solution just created, and after discarding the waste into the proper container, 5.00 mL of the now green buffer solution was added to 3 50 mL beakers. Each beaker had 1.00 mL of a different solution added and a specific label assigned to it: 1.0 M HCl as “Yellow”, 1.0 M NaOH as “Blue” and the last beaker containing water was labeled “Green.” Four cuvettes were cleaned and one was filled with the “Yellow”, another with the “Blue,” a third with the “Green,” and the last cuvette was used as a blank and was filled with distilled water. Using a spectrophotometer and the LoggerPro program on the computer, the spectrums of each solution as varying wavelengths was collected. Starting at 380 nm, the blank was used to calibrate the spectrophotometer. After calibration, the samples were then tested.