A 10 μL aqueous sample containing 1 attogram of Rb+ was injected into a graphite furnace atomic absorption instrument. Calculate the concentration of Rb+ atoms in ppb. The molecular weight of Rb is 85.47 g/mol. density of water = 1.0 g/mL atto = 1 x 10-18 Amazingly, the low concentration of this sample can be detected

A 10 μL aqueous sample containing 1 attogram of Rb+ was injected into a graphite furnace atomic absorption instrument. Calculate the concentration of Rb+ atoms in ppb. The molecular weight of Rb is 85.47 g/mol. density of water = 1.0 g/mL atto = 1 x 10-18 Amazingly, the low concentration of this sample can be detected

Appl Of Ms Excel In Analytical Chemistry

2nd Edition

ISBN:9781285686691

Author:Crouch

Publisher:Crouch

Chapter3: Statistical Tests With Excel

Section: Chapter Questions

Problem 9P

See similar textbooks

Similar questions

To quantify the Cadmium content in a water sample, 5 aliquots of 10 mL were taken, adding to each one of them a volume of a standard solution of Cd (2 mg / mL); after the addition the final volume for all solutions was 50 mL. The absorbance reading was taken in an Atomic Absorption spectrophotometer, the data recorded were: Aliquot 1 2 3 4 5 Cd solution (mL) 0 1 2 3 4 Absorbance 0.163 0.240 0.319 0.402 0.478 Calculate the ppm of Cd.
Quinine in a 1.553-g antimalarial tablet was dissolved in sufficient 0.10 M HCl to give 250 mL of solution.A 10.00-mL aliquot was then diluted to 50.00 mL with the acid. The fluorescence intensity for the dilutedsample at 347.5 nm provided a reading of 196 on an arbitrary scale. A standard 100-ppm quinine solutionregistered 125 when measured under conditions identical to those for the diluted sample. Calculate the massin milligrams of quinine in the tablet.
Copper was determined in a river water sample by atomic absorption spectrometry and the method of standard additions. For the addition, 100.0 µL of a 1000.0 µg/mL Cu standard was added to 100.0 mL of solution. The following data were obtained: Absorbance of reagent blank = 0.020 Absorbance of sample = 0.520 Absorbance of sample plus addition – blank = 1.020 Calculate the copper concentration in the sample.
Caffeine, C8H10O2N4 H2O (MW = 212.2 g/mol) has been shown to have an average absorbance of 0.644 for a concentration of 1.783 mg per 100 mL at 272 nm. A sample of 3.658 g of a soluble coffee product was mixed with water to a volume of 500 mL and a 25 mL aliquot was transferred to a flask containing 25 mL of 0.1 M H2SO4. This was subjected to the prescribed clarification treatment and made up to 500 mL. A portion of this treated solution showed an absorbance of 0.666 at 272 nm. Assumbe b = 1.0 cm. Calculate the % caffeine (w/w) in the sample.
A mixture is prepared by combining 10.72 mL of 2.52 x 10-3 M Fe(NO3)3 with 10.00 mL of 1.76 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 2.25 x 10-4 M.Complete the following ICE table Fe3+ + SCN- ⇌ FeSCN2+ initial (M) (A) (B) (C) change (M) (D) (E) (F) equilibrium (M) (G) (H) (I) What is the value of Kc?
0.1120 g of a solid sample containing copper was dissolved by acid and transferred to a 250.00 mL volumetric flask and volume was made up with distilled water. The solution was then diluted by a factor of 25. The final solution was analyzed by atomic absorption spectrophotometry and the concentration was found be 2.982 ppm, What is the weight percentage of copper in the original solid sample? Keep four significant figures in your final answer.
An unknown concentration of [FeSal]+ gave an absorbance reading of 0.301. Calculate the concentration of the solution, given that the slope of the standard curve was 1280 and the y intercept was -0.00821.
Copper was determined in a river water sample by atomic absorption spectrometry and the method of standard additions. For the addition, 100.0 mL of a 1000.0-mg/mL Cu standard was added to 100.0 mL of solution. The following data were obtained: Absorbance of reagent blank 5 0.020 Absorbance of sample 5 0.520 Absorbance of sample plus addition 2 blank 5 1.020 (a) Calculate the copper concentration in the sample. (b) Later studies showed that the reagent blank used to obtain the above data was inadequate and that the actual blank absorbance was 0.100. Find the copper concentration with the appropriate blank, and determine the error caused by using an improper blank.
Suppose that you are trying to measure the concentration of SO2 in air. To do that, you followed the para-rosaniline method. The SO2 was collected in a 10-ml solution of HgCl4 2- then diluted to 25 ml after the addition of the appropriate reagents. The absorbance owas measured at 650 nm in a 2.0-cm cell, yielding a value of 0.535. A standard sample was prepared by substituting a 1.00 mL sample of a standard solution containing the equivalent of 15.00 ppm SO2 for the airsample. The absorbance of the standard is found out to be 0.191. Report the concentration of SO2 in the air in parts per million. The density of air is 1.19 g/L
Solutions of cobalt (II) ions have a magenta color with a molar absorptivity constant (e) value at 511 nm of 5.87 M-1cm-1. A 0.500 mL sample is transferred from a 50.0 mL stock solution of Co(NO3)2 and diluted with water to a final volume of 7.50 mL. The dilution had an absorbance value at 511 nm in a standard cuvette (1.00 cm light path) of 0.382. Calculate the mass of Co(NO3)2 contained in the original 50.0 mL stock solution.
To determine the concentration of these analyte ions in a mixture, the mixture absorbance is analyzed in a cell with a pathlength of 1.00 cm at 396 nm and at 550 nm, yielding values of 0.109 and 0.0.183, respectively. What is the molar concentrations of X3+ in the sample? What are the molar concentrations of Y2+ in the sample?
(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.