Principles of Instrumental Analysis
7th Edition
ISBN: 9781305577213
Author: Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 9, Problem 9.22QAP
The chromium in an aqueous sample was determined by pipetting 10.0 ml. of the unknown into each of five 50.0-mL volumetric flasks. Various volumes of a standard containing 12.2 ppm Cr were added to the flasks,
following which the solutions were diluted to volume.
Unknown,mL Standard, mL Absorbancc
10.0 0.0 0.201
10.0 10.0 0.292
10.0 20.0 0.378
10.0 30.0 0.467
10.0 40.0 0.554
(a) Plot the data using a spreadsheet.
(b) Determine an equation for the relationship between absorbance and volume of standard.
(c) Calculate the statistics for the least-squares relationship in (b).
(d) I)ctcrmine the conccnt ration oÍCr in ppm in the sample.
(e) Find the standard deviation of the result in (d).
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
10-mL aliquots of an environmental water sample were pipetted into five 50.00-mL volumetric flasks. Exactly 0.00, 5.00, 10.00, 15.00, and 20.00-mL of a standard solution containing 11.1 ppm Fe3+ were added to each, followed by an excess of thiocyanate ion to give the red complex Fe(SCN)2+. After dilution to volume, the instrumental response for each of the five solutions measured with a colorimeter was found to be 0.240, 0.437, 0.621, 0.809, 1.809, respectively.
Using Excel and the LINEST function, what was the concentration in the water sample (including error)? [HINT: consider the type of calibration scheme used.]
4.
determine the amount in mg of the amount of Ag present from ICP
mass digested: 1.0821g/L
dilution of 10ml stock solution to 100ml volumetric flask
X=0.98 (intensity)
The determination of iron in wines was carried out by atomic absorption spectrophotometry, using the standard addition method. To do this, 10 mL of wine were placed in five 50 mL volumetric flasks; then 0, 5, 10, 15 and 20 mL of a 10 ppm iron standard solution were added to each of them.
Next, they were gauged with distilled water and the absorbance was measured, obtaining the values of 0.040, 0.062, 0.081, 0.102 and 0.125 respectively. Calculate the regression parameters and obtain the iron concentration in the wine, in µg / mL.
Chapter 9 Solutions
Principles of Instrumental Analysis
Ch. 9 - Prob. 9.1QAPCh. 9 - Prob. 9.2QAPCh. 9 - Why is an electrothermal atomizer more sensitive...Ch. 9 - Prob. 9.4QAPCh. 9 - Prob. 9.5QAPCh. 9 - Prob. 9.6QAPCh. 9 - Prob. 9.7QAPCh. 9 - Prob. 9.8QAPCh. 9 - Prob. 9.9QAPCh. 9 - Prob. 9.10QAP
Ch. 9 - Prob. 9.11QAPCh. 9 - Prob. 9.12QAPCh. 9 - Prob. 9.13QAPCh. 9 - Prob. 9.14QAPCh. 9 - Prob. 9.15QAPCh. 9 - Prob. 9.16QAPCh. 9 - Prob. 9.17QAPCh. 9 - In the concentration range of 1 to 100 g/mL P,...Ch. 9 - Prob. 9.19QAPCh. 9 - Prob. 9.20QAPCh. 9 - Prob. 9.21QAPCh. 9 - The chromium in an aqueous sample was determined...Ch. 9 - Prob. 9.23QAP
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.Similar questions
- 1 mL was taken from the sample filtrate and mixed with 13 mL pure water and 4 mL sulfomolybdic acid and 2 mL dilute SnCI2 solution by adding it, and after waiting for 15 minutes, the absorbance of the resulting solutions against pure water was read at 520 nm. if the function of the calibration graph obtained with standard phosphorus solutions of 0.5-2.5 mg/mL is y= 0.245x + 0.107 and the absorbance of the serum sample is 0.342, how many grams of phosphorus is the amount in the sample?arrow_forwardThe buret was filled with 0.100 M HCl solution. Then was transferred in a 25.0 mL of saturated calcium hydroxide solution (2g of calcium hydroxide per 100 ml of water) in two separate E-flasks. Then 2 drops of phenolphthalein was added to each flask Titration data for the determination of the common ion effect: Trial 1: Final Buret reading (ml)-29.50; Initial Buret reading (ml)- 26.10; Temperature (Celcius)- 25 Trial 2: Final Buret reading (ml)-33.30; Initial Buret reading (ml)- 29.50; Temperature (Celcius)- 25 Voume of HCl used: Trial 1- 3.40ml; Trial 2- 3.80mL. Report in proper sigfigs. 1. Compute for the moles of H+ used and the moles of OH- present. moles of H+ used = (concentration of HCl) × (volume of HCl used)moles of OH- = moles of H+ used 2. Use the dilution formula to determine the initial concentration of the common ion. C1V1 = C2V2 3. Construct an ICE table for the reaction.4. Calculate the molar solubility…arrow_forwardA 0.0200 gram blood sample was decomposed by a microwave digestion technique followed by dilution to 100.0 mL in a volumetric flask. Aliquots of the sample solution were treated with a lead complexing reagent and water as follows: Solution 1: 10.0 ml blood sample + 20.0 mL complexing agent + 30.0 mL H20. Solution 2: 10.0 ml blood sample + 20.0 mL complexing agent + 26.0 mL H20 + 4.00 mL of 78 ppb Pb2+ standard. The resulting solutions were analyzed by UV/Vis at 375 nm. Absorbance for solution 1 = 0.155 and for solution 2 = 0.216. Calculate the concentration of lead (ppb) in the original sample.arrow_forward
- The buret was filled with 0.100 M HCl solution. Then was transferred in a 25.0 mL of saturated calcium hydroxide solution (2g of calcium hydroxide per 100 ml of water) in two separate E-flasks. Then 2 drops of phenolphthalein was added to each flask Titration data for the determination of the common ion effect: Trial 2: Final Buret reading (ml)-33.30; Initial Buret reading (ml)- 29.50; Temperature (Celcius)- 25 Voume of HCl used: Trial 2- 3.80mL. Report in proper sigfigs. 1. Compute for the moles of H+ used and the moles of OH- present. moles of H+ used = (concentration of HCl) × (volume of HCl used)moles of OH- = moles of H+ used 2. Use the dilution formula to determine the initial concentration of the common ion. C1V1 = C2V2 3. Construct an ICE table for the reaction.4. Calculate the molar solubility (in mol/L) of OH- and Ca2+.5. Determine the solubility of Ca(OH)2 in g/L. (MM of Ca(OH)2 = 74.096 g/mol).…arrow_forwardThe buret was filled with 0.100 M HCl solution. Then was transferred in a 25.0 mL of saturated calcium hydroxide solution (2g of calcium hydroxide per 100 ml of water) in two separate E-flasks. Then 2 drops of phenolphthalein was added to each flask Titration data for the determination of the common ion effect: Trial 2: Final Buret reading (ml)-33.30; Initial Buret reading (ml)- 29.50; Temperature (Celcius)- 25 Voume of HCl used: Trial 2- 3.80mL. Report in proper sigfigs. 1. Calculate the molar solubility (in mol/L) of OH- and Ca2+.2. Determine the solubility of Ca(OH)2 in g/L. (MM of Ca(OH)2 = 74.096 g/mol). 3. Calculate the Ksp of Ca(OH)2. Make sure to include the effect of the common ion in the calculation.arrow_forwardA foot powder sample containing Zn was dissolved on 50.00 mL water and was titrated to the end point color with 22.57 mL of 0.01639 M EDTA at pH=4. (α= 3.61x109, KKzny2 = 3.2 x 1016). The pZn in the sample is:arrow_forward
- What is the mass of pure dry CaCO3 (MW: 100.0869 g/mol) standard used in the standardization of EDTA solution? Assume that 1.758 M EDTA solution was computed based on the titration of CaCO3 standard. The volume of titrant needed to reach the endpoint was 35.00 mL. Ca2+ + Y4- → CaY2- 0.1500 g 5.630 g 6.158 g 0.6158 garrow_forwardThe chlorophyll sample contains Mg2 + ions. Briefly describe the sequencing steps to determine the metal ion concentration in the sample using a simple titration. Which medium is suitable for calibration, acid or basic media, and why?arrow_forwardAnalyze and calculate the percentage of nickel in a 1.201 grams sample of nickel ore which was analyzed by the volumetric method: solution of 48 ml containing 1.40 x 10-2 gram of KCN/ml and the excess cyanide required half a milliliter of silver nitrate solution with 1.25 x 10-2 gram AgNO3 per milliliter.arrow_forward
- An automatic titration was performed with the following results: Standardized NaOH Solution Concentration: 0.1191 M Volume of HA- product examined in each trial: 25.00 mL Volume of Standardized NaOH Titrant used to achieve the first equivalence point: Trial #1: 1.300 mL Trial #2: 1.137 mL Trial #3: 1.140 mL Calculate the %(w/v) for each trial, Average Concetration (%), Deviation (%), Standard Deviation (%), and RSD (%)arrow_forwardLead in dry river sediment was extracted with 25 wt% HNO3 at incubation temperatures for 1 hr. Then 1 mL of filtered extract was combined with other reagents to a total of 4.60 mL. Pb+2 was measured by an electrochemical method by spiking with 2.50 ppm Pb2+. added vol. of 2.50ppm Pb2 signal 0 mL 1.10 0.025 mL 1.66 .050 mL 2.20 .075 mL 2.81 what is Sx based on Syarrow_forwardFive white, 500-mg uncoated ascorbic acid (AA) tablets with an average weight of 0.6100-g were pulverized in a mortar. A sample of the powdered ascorbic acid weighing 0.4610-g was placed in an iodine flask and was dissolved in 50-mL H2SO4 then 5-g of KBr was added to the resulting solution. The solution was titrated with 46.73-mL of 0.0152 M STD. KBrO3 to reach a faint yellow endpoint then 3-g KI and 5-mL Starch TS. The blue color solution is then titrated with 2.78-mL of 0.1047 M STD. Na2S2O3 to reach the disappearance of the blue iodostarch complex. MW: KBrO3 = 167.0 ; KIO3 = 214.0 ; Na2S2O3 = 158.11 ; C6H8O6 = 176.12 Compute the milligrams of pure AA per tablet from the assay. None of the choices 349.7 mg 264.3 mg 462.7 mgarrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Principles of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage Learning
Principles of Instrumental Analysis
Chemistry
ISBN:9781305577213
Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:Cengage Learning
Mass Spectrometry; Author: Professor Dave Explains;https://www.youtube.com/watch?v=hSirWciIvSg;License: Standard YouTube License, CC-BY