Question

Using a chemical equation to find moles of product from moles of reactant

Answer 1

Answer:

0.86 moles H₂O

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