If you begin with 2.48 moles of hydrogen and all the oxygen you need,how many grams of water will you make?

Answer 1

This is a basic Stoichiometry problem so first, you need a balanced equation, which would be as follows:

2 H₂ + O₂ yields 2 H₂O.

From there, you take the 2.48 moles of Hydrogen that you started with and convert it to moles of water using the following equation: 2.48 mol H₂ * 2 mol H₂O/2 mol H₂. The units cancel and so do the 2's so you wind up with 2.48 moles of H₂O, which you then convert to grams by multiplying it by the molecular mass of water (18.016 g/mol). Again, the moles cancel so what you have is 2.48 * 18.016, which equals 44.7 g H₂O (rounded to three significant figures). So if you start with 2.48 moles of Hydrogen, you make 44.7 g of water!