1) First, we need to transform molecules into moles. For this, we use the avogadro constant:
6.023 × 10²³ moleculas ----- 1 mol
6.023 × 10⁴ molecules ------ x mol
x = 6.023 × 10⁴/ 6.023 × 10²³
x = 1 × 10⁻¹⁹ mol
2) Now we need to find the molecular formula of manganese (IV) oxide to find out its molar mass and transform 1 × 10⁻¹⁹ mol into grams (mass of it). The molecular formula of manganese (IV) oxide is MnO₂. So its molar mass: 54.94 + (2x16) = 86.94 g/mol
Now we use the following equation to find out the mass:
mass = moles × molar mass
mass = 1 × 10⁻¹⁹ × 86.94
mass = 86.94 × 10⁻¹⁹
mass = 8.7 × 10⁻¹⁸ grams
Answer: 8.7 × 10⁻¹⁸ grams