0 g of H2 reacts completely with excess O2 to form H2O. How many grams of H2O are produced? Give the final mass on the first line.

36 g H2O are produced. Steps: 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 = 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. 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) = 2.016 + 15.999 = 18.015 g/mol 6. Convert moles of H₂O to grams of H₂O: Mass of H₂O = Moles × Molar mass = 1.984 mol × 18.015 g/mol ≈ 35.74 g H₂O Rounding to two significant figures (due to 4.0 g H₂), the mass of H₂O produced is 36 g.