A 5.00 (10.01) mL. Class A transfer pipet is used to transfer 5.00 ml. of a 0.259 (+0.003) M Cu²+ stock solution to a 100.00 (+0.08) Class A volumetric flask. Deionized water is used to bring the flask to volume. Calculate the concentration of the diluted soluion in the volumetric flask and report its absolute uncertainty. Significant figures are graded for this problem. To avoid rounding errors, do not round your answers until the very end of your calculations. [Cu²+] = M H+ M

6. The concentration of caffeine in an energy soft drink was determined by standard addition using HPLC. The following procedure was used: a standard caffeine solution was prepared by adding 0.09850g of caffeine to 25.0 cm3 of water.A series of solutions were prepared by adding known volumes of the standard solution to the soft drink before diluting to 100 cm3. The volume of standard and the caffeine peak area are shown in the table: Energy Drink (cm3) Added caffeine Std (cm3) Peak area       15 0 965   15 5 1352   15 10 1739   15 15 2126   15 20 2513       Determine the concentration of caffeine in the soft drink as mg cm-3.   A. 3.3 B. 2.3 C. 4.3 D. 7.3

You have a stock solution certified by a manufacturer to contain 205.0 + 0.2 ug So -/mL. You would like to dilute it by a factor of 100 to obtain 2.050 ug/ml. Two possible methods of dilution are stated. For each method, calculate the resulting absolute uncertainty in concentration. Use the manufacturer's tolerances in the table for uncertainties. Glassware Tolerance 1-ml transfer pipet +0.006 ml. 10-ml transfer pipet +0.02 ml. 100-ml volumetric flask +0.08 ml. Method A: Dilute 10.00 mL up to 100 mL with a transfer pipet and volumetric flask. Then take 10.00 ml. of the dilute solution and dilute it again to 100 mL. absolute uncertainty: + Hy/ml Method B: Dilute 1.000 mL up to 100 ml. with a transfer pipet and volumetric flask. absolute uncertainty: + Hy/ml Why is one method more precise than the other? Method B is more precise because the absolute uncertainty in the 1-ml. pipet is 0.006 ml., which is smaller than the uncertainties of the other glassware. Method B is less precise…

02A: 2.1-2.5 and Accuracy Handout (70 min) ulate Figures of Merit for Trueness ▾ Part A. Absolute Error A breathalyzer is a portable electrochemical instrument that measures the concentration of ethyl alcohol in a sample of exhaled breath A forensic chemist checks the calibration of a breathalyzer by testing a standard air sample known to contain 0.174 mg/L of ethanol seven times. The average value of these seven replicate measurements is found to be 0 157 mg/1 Calculate the absolute error of the breathalyzer. 1971 ΑΣΦΑ Submit Previous Answers Request Answer ? Previous x Incorrect; Try Again: 4 attempts remaining Q Search mgl ly Colle 16 of 17 E dx Next 11:44 PM 1/31/202 BANG &

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Often the analyst will compare known quantities of analyte to unknown quantities of the material to be analyzed. This may be done in one of three ways: -use calibration curves; use standard additions; or use internal standards. The method of standard additions would be used when A) the quantity of sample analyzed or the instrument response varies from run to run.   B) the standard solutions and the unknown solution all have similar characteristics are unaffected by the other material in the sample.   C) the sample composition is unknown or complex and affects the analytical signal.

The concentration of acetylsalicylic acid in an antipyretic tablet was determined by HPLC using a normal calibration curve. Standard solutions of acetylsalicylic acid were prepared and analysed using a 10µL loop. The results obtained for the standards are tabulated below: Conc. of Acetylsalicylic Acid (ppm); Signal (arbitrary units) 50; 6352 100; 12869 150; 19175 200; 25536 250; 31936 To determine the concentration of acetylsalicylic acid in an antipyretic tablet, 10 tablets were weighed (6.500 g total) and crushed to a fine powder using a mortar and pestle. A quantity of powder equal the mass of one tablet was added to a 100 mL volumetric flask. The tablet powder was dissolved with 20 mL of methanol and the flask was made to volume using water. The solution was filtered. A 1.000 ml aliquot was transferred to a 10 ml volumetric flask, which was then made to volume with water. Analysis was conducted using a Bio Sil HL C18, 250mm x 4.6mm column; 5um, with a mobile phase of acetonitrile:…

A quality-control laboratory analyzes a product mixture us-ing gas-liquid chromatography. The separation of components ismore than adequate, but the process takes too long. Suggest twoways, other than changing the stationary phase, to shorten theanalysis time