A sample of water from the North Sea was analysed by ion-chromatography and the sulfate concentration was determined to be 2960 mg/L. A sample of formation water from a reservoir near Shetland was analysed by atomic emission spectroscopy and the strontium concentration was determined to be 770 mg/L. If the Ksp value for strontium sulfate is 3. 44x10-7 mo? L2 predict whether precipitation should occur if 500 ml of the seawater is mixed with 500 ml of the formation water.

A sample of water from the North Sea was analysed by ion-chromatography and the sulfate concentration was determined to be 2960 mg/L. A sample of formation water from a reservoir near Shetland was analysed by atomic emission spectroscopy and the strontium concentration was determined to be 770 mg/L. If the Ksp value for strontium sulfate is 3. 44x10-7 mo? L2 predict whether precipitation should occur if 500 ml of the seawater is mixed with 500 ml of the formation water.

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

Chapter1: Introduction

Section: Chapter Questions

Problem 1.9QAP

See similar textbooks

Similar questions

Seawater was spiked with phosphate to achieve a quantifiable range of phosphate concentrations by spectroscopy. What components of the spectrophotometer or sample preparation could be changed that would improve detection limits?
Seawater was spiked with phosphate to achieve a quantifiable range of phosphate concentrations by the spectrophotometer. What components of the spectrophotometer or sample preparation could be changed that would improve detection limits?
Exactly 10.00-mL aliquots of a solution containing phenobarbital were measured into 50.00-mL volumetric flasks and made basic with KOH. The following volumes of a standard solution of phenobarbital containing 2.000μg/mL of phenobarbital were then introduced into each flask and the mixture was diluted to volume: 0.000, 0.500, 1.00, 1.50, 2.00 mL. The fluorescence of each of these solutions was measured with a fluorimeter, which gave values of 3.26, 4.80, 6.41, 8.02, 9.56, respectively. a. plot the data. b. derive a least squares equation for the data plotted in (a). c. find the concentration of phenobarbital from the equation in (b). d. calculate a standard deviation for the concentration obtained in (c).
Inductively coupled plasma–optical emission spectrometry (ICP-OES) was used for the determination of cadmium using indium as an internal standard. A solution containing 2.15 ppm Cd2+ and 5.76 ppm In3+ gave signals of 19,291 and 37,190 counts for cadmium and indium, respectively. A 0.01652 g sample was dissolved in acid and quantitatively transferred to a 250.0 mL volumetric flask. A 1.00 mL aliquot of 264.5 ppm In3+ was added and the flask was diluted to volume with deionized water. ICP-OES analysis of the sample solution gave signals of 31,109 and 118,941 counts for cadmium and indium, respectively. What was concentration of the Cd2+ in the sample? Give answer all questions with explanation
(Standard addition) Tooth enamel consists mainly of the mineral calcium hydroxyapatite, Ca10(PO4)6(OH)2. Trace elements in teeth of archeological specimen provide anthropologists with clues about diet and diseases of ancient people. Student at Dankook University measured the trace element strontium (Sr) in enamel from extracted wisdom teeth by atomic absorption spectroscopy. Solutions were prepared with a constant total volume of 10 mL containing 0.750 mg dissolved tooth enamel plus variable concentrations of added standard Sr. Added Standard Sr (ng/mL=ppb) 0 2.50 5.00 7.50 10.00 Emission Signal 28.0 34.3 42.8 51.5 58.6 (a) Make a graph showing the experimental data and the calculated straight line. (b) Find the concentration of Sr in the tooth ennamel in parts per million = μg/mL.
Chemistry Atomic absorption analysis of Zn gave a calibration best fit line of A=0.670(ppm Zn) The detection limit was determined for this analysis using a 0.020 ppm Zn solution. The standard deviation of the absorbances for 11 samples of the solution was found to be 1.560 x 10-3 and the slope of the calibration curve was 0.026. Calculate the detection limit, Cq, (in units of ppm) for this instrument. Give your answer to 3 places after the decimal place.
An absorbing solution transmits just 38 of every 140 photons to the detector. If the cell width was 2.0 cm and the analyte concentration was 26 mg/L, what was the analyte absorptivity (ppm-1 cm-1)?
A set of three replicate AAS measurements were made from the same calcium standard. Use the information below to determine the LOD for calcium analysis. ⚫ The standard was prepared by dissolving 0.020 g of CaCO, in acid and diluting to 1.000 L. ⚫ After blanking the instrument, the three absorbance readings from the standard were 0.101, 0.096, and 0.104. Hint: Determine the slope of a 'two-point' calibration plot using the blank and average reading of the standard; use the standard deviation of the 3 absorbance readings as s ( )4 ppm ( )3 ppm ( ) 1 ppm ( ) 0.2 ppm
One dietary supplement capsule weighing 4.90 was ground into a fine powder. Two portions of the solid, both weighing 0.200 g, were dissolved in dilute acid, and transferred to 50-mL volumetric flask. To one of these, 5.00 mL of 40.0 ppm manganese ion was added, then both flasks were diluted to the mark with distilled water. When aspirated into the flame of an atomic absorption spectrometer set at a manganese absorption wavelength, the absorbances of the unknown and unknown plus standard were 0.300 and 0.650, respectively. What is the type of calibration method used? a) Standard Addition b) Internal Standard c) External Standard
The measurement of Li in brine (salt water) is used by geochemists to help determine the origin of this fluid in oil fields. Flame atomic absorption of Li is subject to interference by other elements. Atomic absorption of analysis of replicate sample of Li in a brine sample gave results in the table. a. Suggest a reason for the increasing apparent concentration of Li from sample 1 to 2. b. Suggest a reason for the increasing apparent concentration of Li from sample 1 to 3 c. Why do samples 4-6 give a nearly constant result? (What type of interference you think is being eliminated?
1. In using the spectrophotometer PD 303, why is there a need to use water as blank when measuring the absorbance of each solution
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.