Answer:
18.0 g H₂O
Explanation:
To find the mass of water (H₂O), you need to (1) convert grams O₂ to moles O₂ (via the molar mass), then (2) convert moles O₂ to moles H₂O (via mole-to-mole ratio from equation coefficients), and then (3) convert moles H₂O to grams H₂O (via the molar mass). It is important to arrange the conversions in a way that allows for the cancellation of units. The final answer should have 3 sig figs to match the sig figs of the given value.
Molar Mass (O₂): 2(15.998 g/mol)
Molar Mass (O₂): 31.996 g/mol
Molar Mass (H₂O): 2(1.008 g/mol) + 15.998 g/mol
Molar Mass (H₂O): 18.014 g/mol
2 H₂ + 1 O₂ -----> 2 H₂O
16.0 g O₂ 1 mole 2 moles H₂O 18.014 g
--------------- x ---------------- x --------------------- x ----------------- = 18.0 g H₂O
31.996 g 1 mole O₂ 1 mole
