Question

c₂h₆(g) + o₂(g) → express your answer as a chemical equation. identify all of the phases in your answer. view available hint(s) a chemical reaction does not occur for this question.

Explanation:

Step1: Balance carbon atoms

The reactant $\mathrm{C_2H_6}$ has 2 carbon atoms. In the products of combustion of hydrocarbons in oxygen, carbon forms carbon - dioxide $\mathrm{CO_2}$. So we put a coefficient of 2 in front of $\mathrm{CO_2}$: $\mathrm{C_2H_6(g)+O_2(g)
ightarrow 2CO_2(g) + H_2O(l)}$.

Step2: Balance hydrogen atoms

$\mathrm{C_2H_6}$ has 6 hydrogen atoms. In the products, hydrogen forms water $\mathrm{H_2O}$. Since each $\mathrm{H_2O}$ molecule has 2 hydrogen atoms, we need 3 moles of $\mathrm{H_2O}$ to balance the hydrogen atoms: $\mathrm{C_2H_6(g)+O_2(g)
ightarrow 2CO_2(g)+3H_2O(l)}$.

Step3: Balance oxygen atoms

On the right - hand side, we have $2\times2 + 3\times1=7$ oxygen atoms in $2\mathrm{CO_2}$ and $3\mathrm{H_2O}$. On the left - hand side, in $\mathrm{O_2}$, we need $\frac{7}{2}$ moles of $\mathrm{O_2}$ to balance the oxygen atoms: $\mathrm{C_2H_6(g)+\frac{7}{2}O_2(g)
ightarrow 2CO_2(g)+3H_2O(l)}$. To get whole - number coefficients, we multiply the entire equation by 2.

Step4: Get the final balanced equation

$2\mathrm{C_2H_6(g)} + 7\mathrm{O_2(g)}
ightarrow4\mathrm{CO_2(g)}+6\mathrm{H_2O(l)}$

Answer:

$2\mathrm{C_2H_6(g)} + 7\mathrm{O_2(g)}
ightarrow4\mathrm{CO_2(g)}+6\mathrm{H_2O(l)}$