A sample contains 52.0 g of elemental phosphorus, P₄. Determine the number of moles of P₄ and the number of atoms of phosphorus present in the sample.

Question

Quizplus · Accepted Answer

To determine the number of moles of P₄ present in the sample, we need to divide the mass of the sample by its molar mass. The molar mass of P₄ can be calculated by adding the atomic masses of all the atoms present in the molecule: 1 phosphorus atom × 30.97 g/mol = 30.97 g/mol 4 sulfur atoms × 32.06 g/mol = 128.24 g/mol 10 oxygen atoms × 15.99 g/mol = 159.90 g/mol Total molar mass = 30.97 + 128.24 + 159.90 = 319.11 g/mol Number of moles of P₄ = 52.0 g ÷ 319.11 g/mol ≈ 0.419 mol (Option A and C are the only options that have this value) To determine the number of atoms of phosphorus present in the sample, we can use Avogadro's number (6.022 × 10^23 atoms/mol) and the number of moles of P₄: Number of atoms of phosphorus = 1 mol of P₄ × 1 phosphorus atom × 6.022 × 10^23 atoms/mol = 6.022 × 10^23 atoms (Option C is the only option that has this value)

A Sample Contains 52