For the question(s) that follow, consider the following balanced equation.
Mg₃N₂(s) + 6H₂O(l) → 3Mg(OH)₂(s) + 2NH 3 (g)
-How many grams of hydrogen are needed to produce 1.80 g of water according to this equation?
2H₂ + O₂ → 2H₂O

Question

For the question(s) that follow, consider the following balanced equation.
Mg₃N₂(s) + 6H₂O(l) → 3Mg(OH)₂(s) + 2NH 3 (g)
-How many grams of hydrogen are needed to produce 1.80 g of water according to this equation? 
2H₂ + O₂ → 2H₂O

Quizplus · Accepted Answer

To produce 1.80 g of water, we use the molar mass of water (18.02 g/mol) to find moles of water: 1.80 g / 18.02 g/mol = 0.1 mol. From the balanced equation, 2 moles of H₂ produce 2 moles of H₂O, so 0.1 mol of H₂O requires 0.1 mol of H₂. The molar mass of H₂ is 2.02 g/mol, so 0.1 mol of H₂ is 0.1 mol × 2.02 g/mol = 0.202 g, which rounds to 0.200 g.

For the Question(s) That Follow, Consider the Following Balanced Equation