Calculate the exact theoretical number of moles of Carbon dioxide () gas produced when exactly of pu — Mole Concept and Some Basic Concepts of Chemistry Chemistry Question
Question
Calculate the exact theoretical number of moles of Carbon dioxide ($CO_2$) gas produced when exactly $4\text{ moles}$ of pure ethane gas ($C_2H_6$) are burnt inside a sealed reactor containing exactly $14\text{ moles}$ of oxygen gas ($O_2$).
💡 Solution & Explanation
Step 1: Write the balanced combustion equation: $C_2H_6 + 3.5O_2 \rightarrow 2CO_2 + 3H_2O$ (or multiplied by 2: $2C_2H_6 + 7O_2 \rightarrow 4CO_2 + 6H_2O$). Step 2: Determine if there is a limiting reagent. For $C_2H_6$: $4 / 1 = 4$. For $O_2$: $14 / 3.5 = 4$. Since the ratios are identical, both reactants are present in exact, perfect stoichiometric amounts. Neither is limiting or in excess; both are completely consumed. Step 3: Calculate $CO_2$ produced. Using ethane: $1\text{ mole}$ of $C_2H_6$ produces $2\text{ moles}$ of $CO_2$. Therefore, $4\text{ moles}$ will produce $4 \times 2 = 8\text{ moles}$ of $CO_2$.