Adjust the percent transmittance to 100% 4)our out the water in the cuvet, and fill with 2/3 of the reference solution. Read and record absorbance data. Read from lower concentration to higher concentration. 5)Continue to collect absorbance data for al reference and test solutions 6)Dispose of the contents of the cuvets. Data Tables #1 Reference Solutions for the Calibration Curve Sample [FeSCN2+] Absorbance Reference Solution #1 4x10-5 .2034 Reference Solution #2 6x10-5 .3028 Reference Solution #3 8x10-5 .3915 Reference Solution #4 1.0x10-4 .4908 Reference Solution #5 1.2x10-4 .5768 #2 Test Solutions Temperature - 21.9°C Sample [Fe3+] [SCN-] Absorbance Test Solution #6 1.0x10-3 2.0x10-4 .1002 Test
Introduction: Thyme contains a surprising amount of iron compounds. This experiment enables us to determine the amount of iron(II) present in dried thyme by means of a redox reaction. Method: 1. Weigh accurately about 1g of dried thyme and put into a 250cm3 beaker. Record the mass of thyme used.
Experimental Procedure: 250 mL of the copper solution was made by creating 100 mL of the solution, reacting CuO with HNO3, and then diluting to the mark of 250 mL. Using this stock solution, different concentrations were made and placed in the sprectrometer for observation. The absorbances and transmittances were recorded for use when identifying the amount of the color-absorbing copper ions later. A graph was plotted of Absorbance v. Molar Concentration easily see the results of the experiment. Pre-Lab Questions: 1.
Experiment No. : 1 Experiment Tittle: Investigating the effects of a catalyst on the rate of a chemical reaction Surname: Pheto First Name: Tshepo Thatayaone ID Number: 201301288 Day: Friday Date of Experiment: 30 January 2015 Group Members: Seanana G.N 201300771 Seetswane E. 201201591 Onosi G. 201300703 Aim of the experiment The aim of this experiment is to determine the effect of a catalyst on the rate of iodide ion with the peroxodisulphate ion. Summary of the procedure With the use of conical flasks and pipettes,in part A, two solutions were prepared; one contained Potassium persulfate and the other one contained a mixture of 10mL of 0.2M Potassium iodide, 10ML of 0.01M Sodium thiosulphate and 5mL of 0.2% starch. Using water baths, the two solutions were mixed at room temperature, 30ºC, 35ºC, 40ºC and 45ºC. The whole process was repeated but with a catalyst added to the solutions this time for part B.
Purpose: To find the percent of phosphorus in known compound MgNH4PO4*6H2O using gravimetric analysis. Procedure: 1. Weigh by difference to the nearest hundreth gram .75 of your unknown sample, using weighing paper. Using solualbe Expert plant food label percentate 30% P2O5. 2.
To set up the machine and to create a control chart to be used throughout the run, 15 samples were taken with 4 resistors in each sample. The complete list of samples and their measured values is as follows: Develop an X Bar Chart and R Chart and plot the values. What can you tell me about the process? | Sample |1 |2 |3 |4 |mean |range | |1 |1010 |991 |985 |986 |993.00 |25 | |2 |995 |996 |1009 |994 |998.50 |15 | |3 |990 |1003 |1015 |1008 |1004.00 |25 | |4 |1015 |1020 |1009 |998 |1010.50 |22 | |5 |1013 |1019 |1005 |993 |1007.50 |26 | |6 |994 |1001 |994 |1005 |998.50 |11 | |7 |989 |992 |982 |1020 |995.75 |38 | |8 |1001
Name: Robert Christopher Date: 16/2/2011 ID: 0670000687 COMPARISON OF ARTERY AND VEIN Raw Data Table 1: Below are the results of the experiment completed through cutting down the vein and artery into a ring-like shape. A 10g-50g of mass is used to suspend the artery and vein; and measured it with a 1-meter ruler standing 90˚ on the table to distinguish how long it stretches with a specific mass weight. Average Length ± 0.05g/mm | Mass ± 0.05mm/g | Artery | Vein | | Trail 1 | Trial 2 | Average | Trial 1 | Trial 2 | Average | 0g | 393 | 377 | 385 | 370 | 374 | 372 | 10g | 392 | 376 | 384 | 368 | 372 | 370 | 20g | 391 | 375 | 383 | 366 | 370 | 368 | 30g | 390 | 374 | 382 | 364 | 368 | 366 | 40g | 389 | 373 | 381 | 362 | 366 | 364 | 50g | 388 | 372 | 38 | 360 | 364 | 362 | Data Presentation Table 2: Below are the results of the artery and vein’s length difference in mm. These results were known when the average results from the two trials were calculated. The results can be calculated with the following formula: "trial 1 + trial 2; then divide the result by 2 to get the average mean results”.
AP 10006 Test (Total 100 Marks) Question 1(26.28) Consider the following figure. (a) Find the equivalent capacitance between points a and b for the group of capacitors connected as shown in the figure above. Take C1 = 6.00 µF, C2 = 3.0 µF, and C3 = 2.00 µF. (15 marks) (b) What charge is stored on C3 if the potential difference between points a and b is 100.0 V? (15 marks) Answers (a) C1 and C2 in series = 2uF Cupper = 2uF + 2uF + 2uF = 6uF Clower = 3uF + 3uF = 6uF Cequ = 3uF (b) Qupper = Qequ = Cequ V = 3uF100V = 300uC Vupper = Qupper/Cupper = 300uC/6uF = 50V Charge stored in C3 = 2uF50V = 100uC (15 marks) (15 marks) Question 2 (27.53) A charge Q is placed on a capacitor of capacitance C. The capacitor is connected into the circuit as shown in the figure below, with an open switch, a resistor, and an initially uncharged capacitor of capacitance 4C.
Second part of blood was left to coagulate then centrifuged at 3000 rpm for 15 minutes to obtain serum to estimate some biochemical parameters. Serum insulin and leptin were estimated according to the methods of Wilson and Miles, (1977) and Palacio et al. (2002) respectively. (TG) and high density lipoprotein cholesterol (HDL-c) were determined by using enzymatic colorimetric methods described by Kostener et al. (1977).
DCP: Circular Motion Aim: To investigate the effect of the radius of the circle on the time taken for 10 complete revolutions. Raw Data: Radius of Circle/cm (±0.1cm) | Time taken for 10 complete revolutions/s (±0.01s) | Average | | Trial 1 | Trial 2 | Trial 3 | | 25.0 | 4.74 | 5.18 | 4.76 | 4.89 | 30.0 | 5.34 | 5.02 | 4.89 | 5.08 | 35.0 | 5.89 | 5.63 | 5.74 | 5.75 | 40.0 | 6.43 | 6.18 | 6.11 | 6.24 | 45.0 | 6.63 | 6.55 | 6.50 | 6.56 | 50.0 | 7.04 | 6.88 | 6.95 | 6.96 | Figure 1 Calculations: -To find the average I added the results of the three trials together and divided by three. (e.g. : (4.74+5.18+4.76)/3=4.89) Processed Data: Radius of a circle/cm (±0.1cm) | Time taken for 10 complete revolutions/s (±0.01s) | Average time taken for 10 complete revolutions/s | Value | % Uncertainty | Trial 1 | Trial 2 | Trial 3 | Average Value | Absolute Uncertainty | % Uncertainty | 25.0 | ±0.4% | 4.74 | 5.18 | 4.76 | 4.89 | ±0.29 | ±5.9% | 30.0 | ±0.3% | 5.34 | 5.02 | 4.89 | 5.08 | ±0.26 | ±5.1% | 35.0 | ±0.3% | 5.89 | 5.63 | 5.74 | 5.75 | ±0.14 | ±2.4% | 40.0 | ±0.3% | 6.43 | 6.18 | 6.11 | 6.24 | ±0.19 | ±3.0% | 45.0 | ±0.2% | 6.63 | 6.55 | 6.50 | 6.56 | ±0.07 | ±1.1% | 50.0 | ±0.2% | 7.04 | 6.88 | 6.95 | 6.96 | ±0.08 | ±1.2% | Figure 2 Calculations: - For the absolute uncertainty I obtained the result by finding the difference between the mean and the result furthest from it: 5.18(furthest point from mean)-4.89(mean)= 0.29 Absolute uncertainty = ±0.2cm - For the percentage uncertainty I obtained the result by simply dividing the absolute uncertainty by the average and then multiplying by 100: (4.89/0.29)x100=5.9 Percentage uncertainty= ±5.9% Source of Uncertainties Source of uncertainties came mainly from the errors in equipment. The ruler used for the measuring of the radius had an limit of reading of 0.1cm, so