How many atoms are in 0.0728 g of PCl₃? A)1.28 * 10²¹ atoms B)4.38 * 10²² atoms C)4.39 * 10²¹ atoms D)3.19 * 10²⁰ atoms E)6.02 * 10²⁴ atoms

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Quizplus · Accepted Answer

The molar mass of PCl₃ is 137.33 g/mol. So, 0.0728 g of PCl₃ is (0.0728 g / 137.33 g/mol) = 5.29 * 10^-4 mol. Each mole of PCl₃ contains 3 moles of atoms, so 5.29 * 10^-4 mol of PCl₃ contains (3 * 5.29 * 10^-4 mol) = 1.59 * 10^-3 mol of atoms. 1 mol of atoms contains 6.02 * 10²³ atoms, so 1.59 * 10^-3 mol of atoms contains (1.59 * 10^-3 mol * 6.02 * 10²³ atoms/mol) = 9.57 * 10²⁰ atoms.

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