Question

How many grams of H2O are produced when 5.0 g of O2 is completely reacted with excess hydrogen in the stoichiometric reaction 2H2(g) + O2(g) → 2H2O(g)?

a) 5.0 g
b) 10.0 g
c) 15.0 g
d) 20.0 g

Answer 1

To find the number of grams of H2O produced, we can use the stoichiometry of the balanced equation. For 5.0 g of O2, 5.62 g of H2O is produced.

Step-by-step explanation:

To determine the number of grams of H2O produced, we can use the stoichiometric ratio from the balanced equation. For every 2 moles of H2 produced, 2 moles of H2O are produced. Since 5.0 g of O2 is completely reacted, we can use its molar mass to find the number of moles. First, calculate the number of moles of O2: 5.0 g O2 × (1 mol O2 / 32.0 g O2) = 0.15625 mol O2. Now, we can use the stoichiometric ratio to find the number of moles of H2O produced: 0.15625 mol O2 × (2 mol H2O / 1 mol O2) = 0.3125 mol H2O. Finally, convert the moles of H2O to grams: 0.3125 mol H2O × (18.02 g H2O / 1 mol H2O) = 5.62 g H2O.