Calculate the number of moles in 75.0 g of dinitrogen trioxide (N2O3).

Find the molar mass of N₂O₃: (2 × 14.01) + (3 × 16.00) = 76.02 g/mol. Divide the sample mass by the molar mass: 75.0 g ÷ 76.02 g/mol ≈ 0.987 mol. The correct choice is 0.987 mol.

AI-written and checked against the verified answer.