Moles | MCQs

Explanation

Step 1: Calculate the molar mass of S8

The atomic mass of sulfur (S) is approximately 32 g/mol. The molar mass of S8 = 8 * 32 = 256 g/mol.

Step 2: Calculate the number of moles of S8

Number of moles = mass of S8 / molar mass of S8 = 64 g / 256 g/mol = 0.25 mol.

Step 3: Calculate the number of molecules of S8

Number of molecules = number of moles * Avogadro's number (NA) = 0.25 * NA.

Step 4: Calculate the number of sulfur atoms

Each molecule of S8 contains 8 sulfur atoms. Therefore, the total number of sulfur atoms = 8 * number of molecules = 8 * 0.25 * NA = 2 * NA = 2NA.

Explanation

Molar mass of CO₂ = 12 (C) + 16×2 (O) = 44 g/mol

Number of moles = Mass / Molar mass = 60 / 44 ≈ 1.364 mol