Answer:
0.86 moles H₂O
Step-by-step explanation:
To solve this problem, it is important to first determine the balanced chemical equation. The balanced equation is necessary as it will provide the mole-to-mole ratio needed to convert between moles O₂ and moles H₂O.
The unbalanced equation:
C₈H₁₈ (l) + O₂ (g) ---> CO₂ (g) + H₂O (g)
Reactants: 8 carbon, 18 hydrogen, 2 oxygen
Products: 1 carbon, 2 hydrogen, 3 oxygen
As you can see, the equation is not balanced because there are unequal amounts of each element on both sides. Balancing the equation is a matter of guessing-and-checking to see which combination of coefficients work.
The balanced equation:
2 C₈H₁₈ (l) + 25 O₂ (g) ---> 16 CO₂ (g) + 18 H₂O (g)
Reactants: 16 carbon, 36 hydrogen, 50 oxygen
Products: 16 carbon, 36 hydrogen, 50 oxygen
Now that the equation is balanced, we can use the coefficients of O₂ and H₂O to construct our mole-to-mole ratio and perform our conversion. The final answer should have 2 sig figs to match the given value (1.2 moles). The state of matter is most likely not necessary to include in your final answer.
1.2 moles O₂ 18 moles H₂O
--------------------- x ----------------------- = 0.86 moles H₂O
25 moles O₂