The intensities of flame emission lines can be influenced by a variety of instrumental factors including flame temperature, flow rate of solution, and nebulizer efficiency. In the flame emission determination of sodium, lithium is often added as an internal standard. The following emission intensity data were obtained for solutions containing 5.00 ppm Na and 125 ppm Li. 5.00 ppm Na 5.9 Intensity for Na 125 ppm Li 9.1 Intensity for Li A solution with an unknown amount of sodium and 125 ppm Li gave a sodium intensity of 4.4 and a lithium intensity of 9.5. What is the concentration of sodium in the unknown?

The intensities of flame emission lines can be influenced by a variety of instrumental factors including flame temperature, flow rate of solution, and nebulizer efficiency. In the flame emission determination of sodium, lithium is often added as an internal standard. The following emission intensity data were obtained for solutions containing 5.00 ppm Na and 125 ppm Li. 5.00 ppm Na 5.9 Intensity for Na 125 ppm Li 9.1 Intensity for Li A solution with an unknown amount of sodium and 125 ppm Li gave a sodium intensity of 4.4 and a lithium intensity of 9.5. What is the concentration of sodium in the unknown?

Principles of Instrumental Analysis

7th Edition

ISBN:9781305577213

Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Publisher:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Chapter15: Molecular Luminescence Spectrometry

Section: Chapter Questions

Problem 15.10QAP

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Samples X and Y were analysed for Na by flame emission photometry. A series of standard solutions of Na were prepared and Li was added to each standard, as well as to the unknown samples to give a concentration of 5 ppm Li. The following intensities were measured: Determine the Na concentrations in ppm in X and Y samples. Volume (10 ml) of Solution Ratio of Intensities (INa / ILi) - Water (Solvent Blank) - 5 ppm of Na - 10 ppm - 15 ppm - 20 ppm - X - Y - 0.047 - 0.214 - 0.382 - 0.553 - 0.719 - 0.476 - 0.110
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A green solution containing Ni+2 ions absorbs 580 nm light. Undiluted, a sample of this solution sampled in a 1.00 cm diameter cuvette has an absorbance of 0.9765 a.u.. If the molar absorptivity coefficient for Ni+2 is 6.3 x 104 M -1 cm -1 at 580 nm, how much of the original stock Ni+2 solution (in mL) needs to be added to water to create a total dilute solution volume of 10.00 mL that measures an absorbance of 0.146 a.u. at 580 nm? Report your answer to 3 significant figures. Do not include the "mL' unit label in your response
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In the determination of lead content in a solid food sample, 1 g of the solid food sample was extracted with 10 mL of solvent and then diluted to a final volume of 50 mL. A calibration plot of lead standards was obtained from the standard solutions of 1 to 50 ug/mL and it gave a linear regression line of y = 0.025x + 0.004. The wavelength for lead analysis is 283.3 nm. The absorbance value for the extract was 0.302 arbitrary units. Calculate the percentage of Pb in 1 g of the solid food sample.