Question

write a balanced chemical equation based on the following description: liquid c₇h₈o reacts with oxygen gas to produce carbon dioxide gas and water vapor c₇h₈o(l) + o₂(g) →

Explanation:

Step1: Write the unbalanced equation

$$\ce{C_{7}H_{8}O(l) + O_{2}(g) -> CO_{2}(g) + H_{2}O(g)}$$

Step2: Balance carbon atoms

There are 7 carbon atoms in $\ce{C_{7}H_{8}O}$, so we put a 7 in front of $\ce{CO_{2}}$:
$$\ce{C_{7}H_{8}O(l) + O_{2}(g) -> 7CO_{2}(g) + H_{2}O(g)}$$

Step3: Balance hydrogen atoms

There are 8 hydrogen atoms in $\ce{C_{7}H_{8}O}$, so we put a 4 in front of $\ce{H_{2}O}$:
$$\ce{C_{7}H_{8}O(l) + O_{2}(g) -> 7CO_{2}(g) + 4H_{2}O(g)}$$

Step4: Balance oxygen atoms

On the right - hand side, the number of oxygen atoms is \(7\times2 + 4\times1=14 + 4 = 18\). On the left - hand side, the oxygen in $\ce{C_{7}H_{8}O}$ is 1. Let the coefficient of $\ce{O_{2}}$ be \(x\). Then \(1+2x = 18\), so \(2x=17\), \(x=\frac{17}{2}\). Multiply the whole equation by 2 to get rid of the fraction:
$$\ce{2C_{7}H_{8}O(l) + 17O_{2}(g) -> 14CO_{2}(g) + 8H_{2}O(g)}$$

Answer:

$$\ce{2C_{7}H_{8}O(l) + 17O_{2}(g) -> 14CO_{2}(g) + 8H_{2}O(g)}$$