(a)
Interpretation:
The standard addition plot should be constructed.
Concept introduction:
Standard addition method is used to analyze complex samples which matrix effect is significant. One common approach is standard addition technique is spiking of sample. In this method, one or more increments of a standard solution is added to the several aliquots of sample containing same volume. Each solution is then diluted to a fixed volume and experiment is proceeded.
(b)
Interpretation:
The slope and the intercept should be determined.
Concept introduction:
The slope of the line,
The intercept,
(c)
Interpretation:
The standard deviation of the slope and the intercept should be determined.
Concept introduction:
Standard deviation about regression,
N − number of points used.
The standard deviation of the slope,
The standard deviation of the intercept,
(d)
Interpretation:
The concentration of Pd(II) in the analyte solution should be determined.
Concept introduction:
Concentration of the analyte in the sample can be determined by the data obtained from standard-addition method and using following formula.
Cx − concentration of unknown sample
b- intercept
Cs − concentration of the standard sample
m − slope
Vx−volume of unknown sample.
(e)
Interpretation:
The standard deviation of measured concentration should be determined.
Concept introduction:
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Chapter 14 Solutions
Principles of Instrumental Analysis, 6th Edition
- Mixing the chelating reagent B with Ni(II) forms the highly colored NiB22+, whose solutions obey Beer’s lawat 395 nm overa wide range. Provided the analytical concentration of the chelating reagent exceeds that of Ni(II) by a factor of 5 (or more), the cation exists, within the limits of observation, entirely in the form of the complex. Use the accompanying data to evaluate the formation constant Kf for the process Ni2++2BNiB22+arrow_forwardV26arrow_forwardWe have a mixture of 100 mL of Fe3+ solution (1.00 × 10–3 M) and 100 mL of A- ion solution (1.00 × 10–3 M). The mixture has a deep blue color, indicating the formation of a complex between Fe3+ and A-. From spectrophotometric analysis, we find that 30.0% of the Fe3+ is in the form of a complex, where there are two probable formulae: FeX2+ or FeX3. a. Balance the following equations and calculate the concentrations of the remaining species. b. After reaching equilibrium states, write the equilibrium expressions and the equilibrium constants for both cases in (a).arrow_forward
- A series of standard iron-phenanthroline [Fe(phen)3]2+ complex ion solutions were prepared. The absorbance of each solution was measured at a wavelength of 510 mm. A calibration curve of absorbance vs. concentration was then plotted to obtain a linear equation of y = 0.0018x+0.0749. The absorbance of an unknown [Felphenly solution was measured to be 0.326. Calculate the concentration of the complex ion. NOTE! Report your answer as a WHOLE #. Type your answer...arrow_forwardDescribe the principle behind each of the following processes: (i) Vapour phase refining of a metal. (ii) Electrolytic refining of a metal. (iii) Recovery of silver after silver ore was leached with NaCN.arrow_forwardDescribe the application of AAS (Atomic Absorption Spectrophotometry) analytical methods for gold, copper and iron ore deposit evaluation which involve surface and subsurface geochemical sampling in a tropical environment.arrow_forward
- The potassium ion in 250 ml of a water sample was first precipitated as potassium tetraphenylborate: K +(aq) + (C6H5)B- (aq)- KB(C6H5)4 (s). washed, dried and dissolved in an organic solvent. treatment of the organic solution with an excess of aqueous solution of the Hg(ii)-edta complex generated the following reaction: 4HgY2- (aq) +KB(C6H5)4(s) + 4H2O ➜H3BO3, (aq) +4C6H5Hg+(aq) + 4HY3- (aq) + K+ (aq) + OH -(aq) The released edta (in the form of HY3-) was fully titrated with 28.73 ml of 0.04xy mol/l zncl2 solution. Determine the concentration in mg/l of potassium in the water sample. xy is 11arrow_forwardA mixture is prepared by combining 11.34 mL of 2.36 x 103 M Fe(NO3)3 with 10.00 mL of 1.66 x 10-3 M KSCN. The solution turns red due to the formation of FeSCN2+. The absorbance is measured and, using a calibration plot, the [FESCN2*] at equilibrium is found to be 2.20 x 10-4 M. Complete the following ICE table Fe3+ SCN 1t FESCN2+ initial (M) (A) (B) (C)0 change (M) (D) (E) (F) equilibrium (M) (G) (H) (1) What is the value of K?arrow_forwardThe 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.)arrow_forward
- 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)What is the effect on the reported concentration of iron in the sample if there is a trace impurity of Fe2+in the ammonium citrate?arrow_forwardC EDTA extracts bismuth(III) from the bismuth(III)-thiourea (Bi(tu) +) complex according to the reaction, Bi(tu)3++ H, Y²- → BiY¯ + 6 tu + 2H+ 2 where H, Y²- represents the deprotonated form of EDTA. The Bi(tu) + complex exhibits an absorption maximum at 470 nm, whereas the bismuth(III)-EDTA (BiY¯) complex exhibits an absorption maximum at 265 nm. Which of the spectrophotometric titration curves 3+ represent the titration of Bi(tu) + with EDTA when the absorbance is measured at 470 nm? A F B E D Which of the spectrophotometric titration curves represent the titration of Bi(tu)}{} + with EDTA if the 3+ absorbance was instead measured at 265 nm? A B D E F C Absorbance Absorbance Absorbance A Absorbance Volume of titrant Volume of titrant C D Volume of titrant E Absorbance Absorbance Volume of titrant Volume of titrant Volume of titrant F Barrow_forward1) A Chem 102 Student prepared a cobalt coordination compound. Parts "a-c" refer to this problem. a) Next, she analyzed the cobalt content of the compound by preparing a series of known concentration cobalt solutions and prepared a Beer's law graph of absorbance (Y) versus concentration(X). The equation of the line was determined using Excel to be: Y=7.50 X the coordination compound and ultimately diluted it to a total volume of 100.0 mL and measured its absorbance to be 0.310. Calculate the percent cobalt (by mass) in the compound. Where X is concentration in Molarity. She weighed 1.1050 g ofarrow_forward
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