For a Kjeldahl analysis: you weighed 0.0312 g unknown dried blood sample and digested it with concentrated H2SO4. After the distillation into boric acid solution, Methyl Purple indicator changed its color to green. During titration with 0.0110 M H2SO4 it took 15.35 mL of this H2SO4 solution to bring the color of the mixture to grey-blue. a) What number of moles of H2SO4 reacted? b) What number of moles of boric acid reacted with NH3 during distillation? c) What number of moles of NH3 was produced during distillation? d) What was mass of N in the produced NH3? e) What is %N w/w in the original sample?

For a Kjeldahl analysis: you weighed 0.0312 g unknown dried blood sample and digested it with concentrated H2SO4. After the distillation into boric acid solution, Methyl Purple indicator changed its color to green. During titration with 0.0110 M H2SO4 it took 15.35 mL of this H2SO4 solution to bring the color of the mixture to grey-blue. a) What number of moles of H2SO4 reacted? b) What number of moles of boric acid reacted with NH3 during distillation? c) What number of moles of NH3 was produced during distillation? d) What was mass of N in the produced NH3? e) What is %N w/w in the original sample?

Chemistry & Chemical Reactivity

10th Edition

ISBN:9781337399074

Author:John C. Kotz, Paul M. Treichel, John Townsend, David Treichel

Publisher:John C. Kotz, Paul M. Treichel, John Townsend, David Treichel

Chapter4: Stoichiometry: Quantitative Information About Chemical Reactions

Section4.9: Spectrophotometry

Problem 3.1ACP

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