To determine the content of Pb in a canned sausage, 5.00 g were weighed and after adequate treatment they were gauged to a volume of 100 mL, from there an aliquot of 2 mL was taken and brought to a volume of 250 mL. The readings of a series and of the sample were taken in an Atomic Absorption spectrophotometer, recording the following data: mg Pb/mL 0 1 2 3 4 Sample Absorbance 0.00 0.15 0.29 0.44 0.58 0.38 What is the% Pb in canned sausage

A compound with a molecular weight of 229.61 g/mol was dissolved in 50.0 mL of water. 1.00 mL of this solution was placed in a 10.0 mL flask and diluted to the mark. The absorbance of this diluted solution at 510 nm was 0.472 in a 1.000 cm cuvet. The molar absorptivity of the compound, at 510 nm, is 6,310 M-1 cm-1. Calculate the concentration of the compound in the initial 50.0 mL solution. A. 1.50 x 10-5 M B. 7.48 x 10-5 M C. 7.48 x 10-4 M D. 7.48 x 10-6 M

Atomic emission spectroscopy and the method of standard addition are used to determine the Na+ concentration and its uncertainty in an unknown sample. Increasing amounts of a 1.75 ug/mL standard Na+ solution are added to a series of volumetric flasks containing 15.00 mL of the unknown solution. The volumetric flasks are then diluted to a final volume of 200.0 mL. Atomic emission spectroscopy is then used to measure the emission intensity of each solution. Unknown volume Standard volume Final volume Emission (mL) (mL) (mL) intensity 15.00 0.00 200.0 351.0 15.00 5.00 200.0 494.0 15.00 10.00 200.0 642.0 15.00 15.00 200.0 807.0 15.00 20.00 200.0 948.0 Based on the data in the table, determine the original concentration of Nat and its uncertainty in the unknown sample. Report the uncertainty with three significant figures. concentration: ug/mL µg/mL

An absorbance calibration curve for Zn was fitted to equation A = 0.913×`Zn, ppm`.   Flask 1: To the first flask, a 1.00 mL aliquot of the unknown Zn solution was diluted to 100.0 mL in a volumetric flask; the absorption intensity from this sample was measured to be A = 0.204.   Flask 2: To a second flask, a 1.00 mL aliquot of the unknown Zn sample and a 1.00 mL aliquot of 10.00 ppm Zn solution were added and diluted to 100.0 mL in a volumetric flask; the absorbance of this sample was measured to be A = 0.294.   Calculate the % spike recovery for the analysis and report to the nearest whole number.   Hint: A=mC of the type y=mx, so C=A/m   %Spike=100%((Cspike-Coriginal)/Cadded))   Cadded can be found from C1 V1=Cadded V2.