Exactly of pure ozone gas () is subjected to intense heating, resulting in partial decomposition to — Mole Concept and Some Basic Concepts of Chemistry Chemistry Question
Question
Exactly $100\text{ mL}$ of pure ozone gas ($O_3$) is subjected to intense heating, resulting in partial decomposition to oxygen gas ($O_2$). If the final volume of the gaseous mixture increases by exactly $10\text{ mL}$ (measured at the same temperature and pressure), what is the volume of unreacted ozone remaining in the vessel?
💡 Solution & Explanation
Step 1: Write the decomposition reaction. $2O_3(g) \rightarrow 3O_2(g)$. Step 2: Set up volume changes. Let $2x\text{ mL}$ of $O_3$ decompose. Then $3x\text{ mL}$ of $O_2$ is formed. Step 3: Calculate the net increase in volume. Increase = Final Volume - Initial Volume = $3x - 2x = x$. We are given that the increase is $10\text{ mL}$, so $x = 10\text{ mL}$. Step 4: Calculate reacted and remaining $O_3$. Reacted $O_3 = 2x = 20\text{ mL}$. Remaining $O_3 = 100\text{ mL} - 20\text{ mL} = 80\text{ mL}$.