A weighed sample of a copper-nickel alloy is dissolved in a known volume of nitric acid. Which metho — Laboratory Chemistry Question
Question
A weighed sample of a copper-nickel alloy is dissolved in a known volume of nitric acid. Which method is most suitable for determining the mass percent of copper in the alloy?
Treatment of an aliquot of the solution with excess iodide, followed by titration of the iodine produced with sodium thiosulfate.
Measurement of the absorbance of the solution at a wavelength of light at which both Cu2+ and Ni2+ absorb, and comparison with the absorbances of known standards of the two ions.
Addition of excess sodium hydroxide to the solution, isolation of the metal hydroxides by filtration, and measurement of the mass of the precipitate.
Bubbling hydrogen gas through the solution and measuring the mass of the metal that precipitates from the solution.