(6) Calculate the conditional formation constant for the Zn–EDTA complex at pH 9.0 in a solution
0.100 M with respect to ammonia. Can zinc be titrated quantitatively with EDTA solution at this pH?
(7) 0.150 g of an alloy containing some magnesium was dissolved in a suitable solvent. Magnesium
oxinate was precipitated quantitatively, filtered, dried and weighed. The weight of precipitate was 0.250
g. What was the percentage of magnesium in the original sample?
Further Reading
Cooper, D. & Doran, C., Classical Methods, Vol. I, Wiley, Chichester, 1987.
Mendham, J., Dodd, D. & Cooper, D., Classical Methods, Vol. II, Wiley, Chichester, 1987.
Skoog, D. A. & West, D. M., Fundamentals of Analytical Chemistry (4th edn), CBS College
Publishing, New York, 1982.
Jefferey, G. H., Bassett, J., Mendham, J. & Denney, R. C. (eds) Vogel's Textbook of Quantitative
Inorganic Analysis (5th edn), Longman, London, 1989.