An industrial chemical batch of fuming sulphuric acid (oleum) is verified and labelled mathematicall — Mole Concept and Some Basic Concepts of Chemistry Chemistry Question

💡 Solution & Explanation

Step 1: Interpret the label. A rating of "$104.5\%$" strictly implies that $100\text{ g}$ of the sample requires $4.5\text{ g}$ of water to react with all free $SO_3$ to yield $104.5\text{ g}$ of pure $H_2SO_4$. Statements A and D are chemically true. Step 2: Determine free $SO_3$. The reaction is $H_2O + SO_3 \rightarrow H_2SO_4$. $18\text{ g}$ of water neutralizes $80\text{ g}$ of $SO_3$. Thus, $4.5\text{ g}$ of water will neutralize $\left(\frac{80}{18}\right) \times 4.5 = 20\text{ g}$ of $SO_3$. Statement B is true. Step 3: Determine initial $H_2SO_4$. The total initial mass was $100\text{ g}$. Since $20\text{ g}$ is free $SO_3$, the remaining $80\text{ g}$ must be the carrier solvent, which is $H_2SO_4$. Statement C is true.