please post other questions
separately
Question 4 (2 points) A working standard 1 is prepared by taking 24.00 mL of a...
5
A calibration curve used in UV/VIS spectroscopy plots concentration on the y-axis and absorbance on the x-axis. O A) True OB) False Question 5 (2 points) A working standard is prepared by taking 38.00 mL of a 500.0 ppm stock solution and diluting it tos a final volume of 650.0 mL. Calculate the ppm concentration of the working solution. Provide your answer to two places after the decimal and without units. Your Answer: Answer Submit Out 2afactione ad
show calculations please
3. A standard solution of Fe(II) [10.0 ppm) was prepared, the appropriate reagents were added, and a series of standard solutions were prepared and the transmittance of the solutions were read out as follows: Vol. of std solution (ml) Final vol. (mL) %T 0.00 100.0 100.0 5.00 100.0 77.7 25.00 100.0 30.2 50.00 100.0 10.4 (a) (3 pts) plot a calibration curve and find out the slope and y-intercept for the linearly related Absorbance with concentration. (b)...
1. A student makes a solution by mixing 7.0 mL of a 4.5 x 10 M solution of Allura Red and 3.0 ml of water. What is the concentration of Allura Red in the resulting solution? A student is interested in the concentration of blue dve in his favorite beverage. He knows that spectroscopy can be used to determine the concentration of dye molecules in a solution. After making several solutions of known concentration, the student measured the absorbance of...
Question 2 Compound "Y" (molar mass = 480.5 g moll) used as a food coloring. Following experiment was carried out to find the concentration of "Y" in a beverage. A stock solution of compound "Y" (concentration = 7.50 0 10-4 mol L-) was used to prepare a series of standard solutions. Calibrated pipets and 100.0 mL volumetric flasks were used for these preparations. Then, absorbance of these solutions were measured at 460 nm using 1-cm cuvettes. A dilution was carried...
You prepared standard benzoic acid and caffeine solutions that allowed you to produce four standard curves with the linear equations listed below. You also diluted an unknown solution by taking a 4 mL aliquot with a volumetric pipet and transferring it into a 100 mL volumetric flask that contained 10 mL of 0.10 M HCl. You then diluted it to the mark with Dl water. You measured the absorbance at both wavelengths for the diluted unknown. The data is shown...
Pure solid NaH2PO4 is dissolved in distilled water, making 100.00 ml of solution. 10.00ml of this solution is diluted to 100.00 ml to prepare the original phosphate standard solution. Three working standard solutions are made from this by pipetting 0.8ml, 1.5ml and 3.0 ml of the original standard solution into 100.00 ml volumetric flasks. Acid and molybdate reagent are added and the solutions are diluted to 100.00 ml. You may assume that all these absorbance measurements have already been corrected...
If a mixture was prepared by diluting 7.0 mL of the Blue#1 solution with water to a final volume of 10.0 mL and mixing this with 2.0 mL of diluted bleach how many seconds would it require for the mixture to have an absorbance of 0.120? Use your measured values of eb and of the average rate constant, k to answer this question. Show all work. eb= 0.1138 k= -0.035 first order reaction Concentration of Blue Solution= 15 M
A student prepares a caffeine standard solution that has a concentration of 1858 ppm. To prepare a calibration curve, the student pipets various volumes of the standard solution into 50.0 mL volumetric flasks and dilutes to the fill line with water. The absorbance of each solution is measured in a 1.00 cm cuvette using the spectrophotometer and is shown in the table below. Calculate the concentration of each solution and create a calibration curve using the absorbance data provided. Based...
3. a) A standard ZnCl2 solution is prepared by dissolving 0.6483 g of Zn in an HCl solution and diluting to volume in a 1.00 L volumetric flask. An EDTA solution is standardized by titrating a 15.00 mL aliquot of the ZnCl2 solution, which requires 16.12 mL of EDTA solution to reach the end point. Determine the concentration of the EDTA solution. (2 pts) b) A 1.5146 g sample of powdered milk is dissolved and the solution titrated with...
4) An unknown concentration of NiSO4 solution is to be determined by colorimetric analysis using a spectrophotometer. The standard solutions are prepared as the following: 2.00 mL (the same procedures for 3.0 mL, 4.00 mL, 6.00 mL, 7.00 mL) of the stock solution of 1.00 M NİSO4 is transferred into a 25-mL volumen flask and diluted by adding distilled water to the mark line. The spectrophotometer is calibrated at the wavelength of 635 nm. The absorbance (A) readings and the...