Which of the following is the correct molecular equation for the reaction between strontium nitrate and potassium iodate?

• A. Sr(NO3)2(aq) + KIO3(aq) → Sr(IO3)2(s) + KNO3(aq)
• B. Sr(NO3)2(aq) + 2KIO3(aq) → Sr(IO3)2(s) + 2KNO3(aq)
• C. Sr(NO3)2(s) + 2KIO3(aq) → Sr(IO3)2(aq) + 2KNO3(aq)
• D. Sr(NO3)2(aq) + KIO3(aq) → Sr(IO3)2(aq) + KNO3(s)

Answer: (B)

Verified step by step guidance

1. Identify the reactants and products in the given chemical reaction. The reactants are strontium nitrate \( \text{Sr(NO}_3\text{)}_2 \) and potassium iodate \( \text{KIO}_3 \). The products are strontium iodate \( \text{Sr(IO}_3\text{)}_2 \) and potassium nitrate \( \text{KNO}_3 \).
2. Determine the physical states of each compound. Strontium nitrate \( \text{Sr(NO}_3\text{)}_2 \) and potassium iodate \( \text{KIO}_3 \) are aqueous \((aq)\), meaning they are dissolved in water. Strontium iodate \( \text{Sr(IO}_3\text{)}_2 \) is a solid \((s)\), indicating it precipitates out of the solution. Potassium nitrate \( \text{KNO}_3 \) remains aqueous \((aq)\).
3. Write the balanced molecular equation. Balance the equation by ensuring the number of atoms of each element is the same on both sides of the equation. Start by balancing the strontium \( \text{Sr} \) and nitrate \( \text{NO}_3 \) ions, then balance the potassium \( \text{K} \) and iodate \( \text{IO}_3 \) ions.
4. Check the stoichiometry of the reaction. The balanced equation should reflect the correct stoichiometric coefficients. For every one mole of strontium nitrate \( \text{Sr(NO}_3\text{)}_2 \), two moles of potassium iodate \( \text{KIO}_3 \) are required to produce one mole of strontium iodate \( \text{Sr(IO}_3\text{)}_2 \) and two moles of potassium nitrate \( \text{KNO}_3 \).
5. Verify the balanced equation: \( \text{Sr(NO}_3\text{)}_2(aq) + 2\text{KIO}_3(aq) \rightarrow \text{Sr(IO}_3\text{)}_2(s) + 2\text{KNO}_3(aq) \). Ensure that the equation is consistent with the law of conservation of mass, where the total number of atoms for each element is equal on both sides of the equation.