Ask Question
10 February, 20:31

Chalcopyrite, the principal ore of copper (Cu), contains 34.63 percent Cu by mass. How many atoms of Cu can be obtained from 5.11 x 103 kg of ore? A) 1.68 x 1028 Cu atoms B) 1.68 x 1025 Cu atoms C) 6.77 x 1031 Cu atoms D) 6.77 x 1034 Cu atoms

+3
Answers (1)
  1. 10 February, 23:34
    0
    A) 1.68 x 10²⁸ Cu atoms.

    Explanation:

    ∵ The mass of Cu in the chalcopyrite ore = mass of the ore x weight fraction of Cu.

    Weight fraction of Cu = Weight % / 100 = 34.63 / 100 = 0.3463.

    ∴ The mass of Cu in the chalcopyrite ore = mass of the ore x weight fraction of Cu = (5.11 x 10³ kg) (0.3463) = 1.77 x 10³ kg.

    We need to calculate the no. of moles of Cu atoms:

    n of Cu = mass/atomic mass of Cu = (1770 x 10³ g) / (63.54 g/mol) = 27.853 x 10³ mol.

    We have that every mole of an element contains Avogadro's no. of atoms (6.022 x 10²³).

    ∴ 27.853 x 10³ mol of Cu contains = (27.853 x 10³ mol) (6.022 x 10²³) = 1.677 x 10²⁸ Cu atoms ≅ 1.68 x 10²⁸ Cu atoms.
Know the Answer?
Not Sure About the Answer?
Find an answer to your question ✅ “Chalcopyrite, the principal ore of copper (Cu), contains 34.63 percent Cu by mass. How many atoms of Cu can be obtained from 5.11 x 103 kg ...” in 📘 Chemistry if you're in doubt about the correctness of the answers or there's no answer, then try to use the smart search and find answers to the similar questions.
Search for Other Answers