Question

liquid octane reacts with oxygen gas to form carbon dioxide gas and water vapor. express your answer as a chemical equation. identify all of the phases in your answer. a chemical reaction does not occur for this question.

Explanation:

Step1: Write the reactants

The reactants are liquid octane ($C_8H_{18}(l)$) and oxygen gas ($O_2(g)$).

Step2: Write the products

The products are carbon - dioxide gas ($CO_2(g)$) and water vapor ($H_2O(g)$).

Step3: Balance the equation

First, balance the carbon atoms. There are 8 carbon atoms in octane, so we need 8 moles of $CO_2$. Then balance the hydrogen atoms. There are 18 hydrogen atoms in octane, so we need 9 moles of $H_2O$. Finally, balance the oxygen atoms. On the right - hand side, we have $8\times2 + 9\times1=25$ oxygen atoms. So we need $\frac{25}{2}$ moles of $O_2$. Multiply the entire equation by 2 to get whole - number coefficients.
The balanced chemical equation is $2C_8H_{18}(l)+25O_2(g)
ightarrow16CO_2(g) + 18H_2O(g)$

Answer:

$2C_8H_{18}(l)+25O_2(g)
ightarrow16CO_2(g) + 18H_2O(g)$