0 g of H2 reacts completely with excess O2 to form H2O. How many grams of H2O are produced?

36 g of H2O are produced. Here are the steps to calculate the mass of H2O produced: 1. Write the balanced chemical equation: 2H₂(g) + O₂(g) → 2H₂O(l) 2. Calculate the molar mass of H₂: Molar mass of H₂ = 2 × 1.008 g/mol = 2.016 g/mol 3. Convert the mass of H₂ to moles of H₂: Moles of H₂ = Mass / Molar mass Moles of H₂ = 4.0 g / 2.016 g/mol = 1.984 mol H₂ 4. Use the mole ratio from the balanced equation to find moles of H₂O: From the balanced equation, 2 moles of H₂ produce 2 moles of H₂O. Therefore, Moles of H₂O = Moles of H₂ = 1.984 mol H₂O 5. Calculate the molar mass of H₂O: Molar mass of H₂O = (2 × 1.008 g/mol) + (1 × 15.999 g/mol) = 18.015 g/mol 6. Convert moles of H₂O to grams of H₂O: Mass of H₂O = Moles × Molar mass Mass of H₂O = 1.984 mol × 18.015 g/mol = 35.74 g 7. Round to appropriate significant figures: Since the given mass (4.0 g) has two significant figures, the answer should also be rounded to two significant figures. Mass of H₂O ≈ 36 g