A 12 g sample of P^4O^10 contains how many

molecules of phosphorus pentaoxide?

molecules P4O10 = 2.546 E22 molecules

Explanation:

mol ≡ 6.022 E23 molecules

∴ mass P4O10 = 12 g

∴ mm P4O10 = 283.886 g/mol

⇒ mol P4O10 = (12 g) * (mol/283.886 g) = 0.0423 mol P4O10

⇒ molecules P4O10 = (0.0423 mol P4O10) * (6.022 E23 molecules/mol)

⇒ molecules P4O10 = 2.546 E22 molecules