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

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.

∴ 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.

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

∴ 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.

the correct answer would be b) volume versus temperature, because they are also directly proportional.