This chemistry question involves key chemical concepts and calculations. The detailed solution below walks through each step, from identifying the reaction type to computing the final answer.
ScanSolve AI Answer
When 4.0 g of H2 reacts with excess O2, 36 g of water are produced. Steps: 1. Calculate moles of H2: Molar mass of H2 = 2 * 1.008 g/mol = 2.016 g/mol Moles of H2 = Mass / Molar mass = 4.0 g / 2.016 g/mol = 1.984 mol H2 2. Use stoichiometry to find moles of H2O: From the balanced equation (2H2 + O2 -> 2H2O), 2 moles of H2 produce 2 moles of H2O. Moles of H2O = Moles of H2 * (2 mol H2O / 2 mol H2) = 1.984 mol H2O 3. Calculate mass of H2O: Molar mass of H2O = (2 * 1.008 g/mol) + 15.999 g/mol = 18.015 g/mol Mass of H2O = Moles of H2O Molar mass = 1.984 mol 18.015 g/mol = 35.74 g 4. Round to appropriate significant figures: The initial mass (4.0 g) has two significant figures, so the final answer should also have two significant figures. Mass of H2O = 36 g