Given parameters: Mass of water to be decomposed = 29.2g Unknown: Number of moles of oxygen. Solution: To solve this problem, we first write the balanced reaction equation : 2H₂O → 2H₂ + O₂ Now convert the given mass of the water to number of moles; Number of moles of water = Molar mass of water = 2(1) + 16 = 18g/mol Number of moles of water = = 16.2moles From the balanced reaction equation: 2 moles of water produced 1 mole of oxygen gas; 16.2 mole of water will produce = 8.1moles of oxygen gas
