Question

If you have half a mole of octane (c8h18), how much water is produced? 2c8h18 + 25o2 --> 16co2 + 18h2o

Answer 1

Answer:

4.5 moles H₂O

       or

81.072 g H₂O

Explanation:

I am not exactly sure whether you want moles H₂O or grams H₂O. So, I'll calculate both. To find the moles H₂O, you'll need to covert moles C₈H₁₈ to moles H₂O via the mole-to-mole ratio from the reaction coefficients. To find the grams H₂O, you need to convert moles H₂O to grams H₂O via the molar mass.

2 C₈H₁₈ + 25 O₂ ---> 16 CO₂ + 18 H₂O

0.5 mole C₈H₁₈          18 moles H₂O
-----------------------  x  -------------------------  = 4.5 moles H₂O
                                  2 moles C₈H₁₈

Molar Mass (H₂O): 2(1.008 g/mol) + 16.00 g/mol

Molar Mass (H₂O): 18.016 g/mol

4.5 moles H₂O         18.016 g
----------------------  x  ----------------  =  81.072 g H₂O
                                  1 mole