Li, „CoO, is an anode for lithium batteries. Cobalt is present as a mixture of Co(III) and Co(II). Most preparations also contain inert lithium salts and moisture. To find the stoichiometry, Co was measured by atomic absorption and its average oxidation state was measured by a potentiometric titration.43 For the titration, 25.00 mg of solid were dissolved under N, in 5.000 mL containing 0.1000 M Fe2+ in 6 M H,SO, plus 6 M H, PO, to give a clear pink solution: Co+ + Fe2+ - Co2+ + Fe3+ Unreacted Fe2+ required 3.457 mL of 0.01487 M K,Cr,0, for complete titration. How many mmol of Co³ + are contained in 25.00 mg of the material? mmol of Co3 + mmol Atomic absorption found 56.4 wt% Co in the solid. What is the average oxidation state of Co? average oxidation state of Co: Find y in the formula Li, 4COO,. y = What is the theoretical quotient wt% Li/wt% Co in the solid? wt% Li wt% Co The observed quotient, after washing away inert lithium salts, was 0.1388 ± 0.0006. Is the observed quotient consistent with the average cobalt oxidation state? O yes no

Li, „CoO, is an anode for lithium batteries. Cobalt is present as a mixture of Co(III) and Co(II). Most preparations also contain inert lithium salts and moisture. To find the stoichiometry, Co was measured by atomic absorption and its average oxidation state was measured by a potentiometric titration.43 For the titration, 25.00 mg of solid were dissolved under N, in 5.000 mL containing 0.1000 M Fe2+ in 6 M H,SO, plus 6 M H, PO, to give a clear pink solution: Co+ + Fe2+ - Co2+ + Fe3+ Unreacted Fe2+ required 3.457 mL of 0.01487 M K,Cr,0, for complete titration. How many mmol of Co³ + are contained in 25.00 mg of the material? mmol of Co3 + mmol Atomic absorption found 56.4 wt% Co in the solid. What is the average oxidation state of Co? average oxidation state of Co: Find y in the formula Li, 4COO,. y = What is the theoretical quotient wt% Li/wt% Co in the solid? wt% Li wt% Co The observed quotient, after washing away inert lithium salts, was 0.1388 ± 0.0006. Is the observed quotient consistent with the average cobalt oxidation state? O yes no

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

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