if 6.3 moles of ethylene (C2H4) reacts with excess O2 how many moles of water will be produced? C2H4 + 3O2 -> 2CO2 + 2H2O

Answer 1

Hello, Lota,

The equation is correctly balanced. It tells us that we get 2 moles of water for every 1 mole of ethylene consumed. Since we have excess oxygen, we can simply ask how many moles of water will come from the entire 6.3 moles of ethylene. We already decided that the molar ratio of water to ethylene is 2 (H₂)/(C₂H₄).

We can invert that to (1(C₂H₄)/(2 (H₂O), or (1/2)(mole H₂O)/(mole C₂H₄)

Therefore:

(6.3 moles C₂H₄)*(1/2)(mole H₂O)/(mole C₂H₄) = 3.15 mole H₂O

.2 moles with 2 sig figs

Bob