write a balanced chemical equation based on the following description: liquid c₇h₈o reacts with oxygen gas…

Explanation:

Step1: Write the unbalanced equation

$$\mathrm{C_7H_8O(l) + O_2(g)\rightarrow CO_2(g)+H_2O(g)}$$

Step2: Balance carbon atoms

There are 7 carbon atoms in $\mathrm{C_7H_8O}$. So, we put a coefficient of 7 in front of $\mathrm{CO_2}$: $$\mathrm{C_7H_8O(l) + O_2(g)\rightarrow 7CO_2(g)+H_2O(g)}$$

Step3: Balance hydrogen atoms

There are 8 hydrogen atoms in $\mathrm{C_7H_8O}$. So, we put a coefficient of 4 in front of $\mathrm{H_2O}$: $$\mathrm{C_7H_8O(l) + O_2(g)\rightarrow 7CO_2(g)+4H_2O(g)}$$

Step4: Balance oxygen atoms

On the right - hand side, the number of oxygen atoms in $7\mathrm{CO_2}$ is $7\times2 = 14$ and in $4\mathrm{H_2O}$ is $4\times1=4$. So, total oxygen atoms on the right - hand side is $14 + 4=18$. In $\mathrm{C_7H_8O}$, there is 1 oxygen atom. Let the coefficient of $\mathrm{O_2}$ be $x$. Then $1+2x=18$, which gives $2x = 17$, but we can also balance by multiplying the entire equation by 2 to get rid of fractions.

Multiply the whole equation by 2: $$\mathrm{2C_7H_8O(l) + 17O_2(g)\rightarrow 14CO_2(g)+8H_2O(g)}$$

Answer:

$$\mathrm{2C_7H_8O(l) + 17O_2(g)\rightarrow 14CO_2(g)+8H_2O(g)}$$