An unknown sample of Cu2+ gave an absorbance of 0.292 in an atomic absorption analysis. Then 2.00 mL of solution containing 100.0 ppm (= µg/mL) Cu2+ was mixed with 95.0 mL of unknown, and the mixture was diluted to 100.0 mL in a volumetric flask. The absorbance of the new solution was 0.462.
(a) Denoting the initial, unknown concentration as [Cu2+]i, write an expression for the final concentration, [Cu2+]f, after dilution. Units of concentration are ppm.
WebAssign will check your answer for the correct number of significant figures. [Cu2+]i
(b) In a similar manner, write the final concentration of added standard Cu2+, designated as [S]f .
WebAssign will check your answer for the correct number of significant figures. ppm
(c) Find [Cu2+]i in the unknown.
WebAssign will check your answer for the correct number of significant figures. ppm