Question

One way in which the useful metal copper is produced is by dissolving the mineral azurite, which contains copper (II) carbonate, in concentrated sulfuric acid. The sulfuric acid reacts with the copper (II) carbonate to produce a blue solution of copper (II) sulfate. Scrap iron is then added to this solution, and pure copper metal precipitates out because of the following chemical reaction: Fe(s) + CuSO4 (aq) rightarrow Cu (s) + FeSO4 (aq) Suppose an industrial quality-control chemist analyzes a sample from a copper processing plant in the following way. He adds powdered iron to a 250. mL copper (II) sulfate sample from the plant until no more copper will precipitate. He then washes, dries, and weighs the precipitate, and finds that it has a mass of 96. mg . Calculate the original concentration of copper (II) sulfate in the sample. Be sure your answer has the correct number of significant digits.

Answer 1

Answer:

6,04x10⁻³M

Explanation:

For the reaction:

Fe(s) + CuSO₄(aq) → Cu(s) + FeSO₄(aq)

The precipitate of Cu(s) weights 96,0 mg. In moles:

Moles of Cu(s):

0,096g×(1mol/63,546g) = 1,51x10⁻³ moles of Cu(s). If you see the balanced equation 1 mole of CuSO₄ produce 1 mole of Cu(s). That means moles of CuSO₄ are the same of Cu(s), 1,51x10⁻³ moles of CuSO₄

As volume of the solution is 250 mL, 0,250L, the molar concentration of the original solution is:

1,51x10⁻³ moles of CuSO₄ / 0,250L = 6,04x10⁻³M

I hope it helps!