Principles of Instrumental Analysis
7th Edition
ISBN: 9781305577213
Author: Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher: Cengage Learning
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Chapter 14, Problem 14.8QAP
Interpretation Introduction
(a)
Interpretation:
The molar concentration of nickel and cobalt in a solution should be determined.
Concept introduction:
The Beer-Lambert Law
A − absorbance
⁊ - molar absorptivity
l − length of the solution light passes through (cm)
c − concentration of solution (mol/L)
Interpretation Introduction
(b)
Interpretation:
The molar concentration of nickel and cobalt in a solution should be determined.
Concept introduction:
The Beer-Lambert Law
A − absorbance
⁊ - molar absorptivity
l − length of the solution light passes through (cm)
c − concentration of solution (mol/L)
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The red color of soil is often due to the presence of iron. Metal ions are extracted from soil by stirring the soil in acid and then filtering the solution. One method for the analysis of Fe2+ is to form the highly colored Fe2+–thioglycolic acid complex. The complex absorbs strongly at 535 nm.
Calibration standards of 1.00, 2.00, 3.00, 4.00, and 5.00 ppm are prepared by transferring appropriate amounts of a 10.0 ppm working solution of Fe2+ into separate 50-mL volumetric flasks, each of which contains 5 mL of thioglycolic acid, 2 mL of 20% w/v ammonium citrate, and 5 mL of 0.22 M NH3. After diluting to volume and mixing, the absorbances of the standards are measured.
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The red color of soil is often due to the presence of iron. Metal ions are extracted from soil by stirring the soil in acid and then filtering the solution. One method for the analysis of Fe2+ is to form the highly colored Fe2+–thioglycolic acid complex. The complex absorbs strongly at 535 nm.
Calibration standards of 1.00, 2.00, 3.00, 4.00, and 5.00 ppm are prepared by transferring appropriate amounts of a 10.0 ppm working solution of Fe2+ into separate 50-mL volumetric flasks, each of which contains 5 mL of thioglycolic acid, 2 mL of 20% w/v ammonium citrate, and 5 mL of 0.22 M NH3. After diluting to volume and mixing, the absorbances of the standards are measured.
a)Use the data table below to prepare a calibration curve (absorbance versus concentration in ppm). Fit the data to straight line and find the equation for the straight line and the R2 value. (Hint: Think about what to do with the absorbance of the blank.)
Chapter 14 Solutions
Principles of Instrumental Analysis
Ch. 14 - Prob. 14.1QAPCh. 14 - A 0.4740-g pesticide sample was decomposed by wet...Ch. 14 - Sketch a photometric titration curve for the...Ch. 14 - Prob. 14.4QAPCh. 14 - Prob. 14.5QAPCh. 14 - The accompanying data (1.00-cm cells) were...Ch. 14 - A 3.03-g petroleum specimen was decomposed by wet...Ch. 14 - Prob. 14.8QAPCh. 14 - Prob. 14.9QAPCh. 14 - The acid-base indicator HIn undergoes the...
Ch. 14 - Prob. 14.11QAPCh. 14 - Prob. 14.12QAPCh. 14 - Copper(II) forms a 1:1 complex with the organic...Ch. 14 - Aluminum forms a 1:1 complex with...Ch. 14 - Prob. 14.15QAPCh. 14 - Prob. 14.16QAPCh. 14 - Prob. 14.17QAPCh. 14 - Prob. 14.18QAPCh. 14 - Prob. 14.19QAPCh. 14 - Given the Information that...Ch. 14 - Prob. 14.21QAPCh. 14 - Mixing the chelating reagent B with Ni(II) forms...Ch. 14 - Prob. 14.23QAP
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