A recycling company has purchased several tons of scrap wire that is known to contain silver. A sample of wire with a mass of 2.0764 g is completely dissolved in nitric acid. Then dilute hydrochloric acid is added until precipitation stops. The precipitate is filtered, dried thoroughly, and weighed. The precipitate has a mass of 0.1656 g. Assuming that the precipitate is pure AgCl, what is the percentage by mass of silver in the wire sample?

Strategy

Determine the amount of silver in the AgCl formed in the precipitation reaction. To do this, calculate the number of moles of given species (silver chloride in the precipitate) from the given data. Use the stoichiometry in the chemical equation to determine the number of moles of desired species, Ag, present in the sample. Convert this number of moles to grams, and determine the mass percentage of Ag in the original sample.