**Analytical Chemistry Atomic Absorption*** Finding the concentration of unknown titanium sample.

User Generated

Beovgny

Science

Description

Mn=internal standard to measure Fe by Atomic Absorption.

ug= micrograms

Standard mixture: 2 ug Mn/mL & 2.50 ug Fe/mL gave quotient (signal?) of 1.05/1.00. A mixture with  a volume of 6 mL was prepared by mixing 5 mL of unknown Fe solutionn w/1 mL containing 13.5 ug Mn/mL.

Absorbance of Mn: 0.128

Absorbance of Fe: 0.185

Find the molarity of the Unknown Fe solution.

User generated content is uploaded by users for the purposes of learning and should be used following Studypool's honor code & terms of service.

Explanation & Answer


Airon=(Kiron)(Ciron)
Amn=(Kmn)(Cmn)
Airon/Amn= 1.05 = (Kiron)(2.50) / (Kmn)(2.00) 

Kiron/Kmn = 0.84


(Kiron)(Ciron) =0.370

(Kmn)(13.5/6)=0.128 

Divide the top equation by the bottom one: 

2.891 = (Kiron / Kmn)*(Ciron / 2.25) = (0.84)*(Ciron / 2.25) 

Ciron(after mixing) = 7.743 mg/L 

Ciron(actual) = 7.743*(6/5) = 9.29 mg/L 

9.29 mg/L * (1 g / 1000 mg) / (55.8 g/mol) = 1.66 * 10^-4 M

Related Tags