In a reaction between Mg^{2+} ions and Cl^{-} ions to form MgCl_2, how many moles of Cl^{-} ions are required to completely combine with 0.25 moles of Mg^{2+} ions?

• A. 0.75 moles
• B. 1.00 mole
• C. 0.25 moles
• D. 0.50 moles

Answer: (D)

Verified step by step guidance

1. Write the balanced chemical equation for the reaction between magnesium ions and chloride ions: \(\mathrm{Mg^{2+} + 2Cl^{-} \rightarrow MgCl_2}\).
2. Identify the mole ratio between \(\mathrm{Mg^{2+}}\) ions and \(\mathrm{Cl^{-}}\) ions from the balanced equation. For every 1 mole of \(\mathrm{Mg^{2+}}\), 2 moles of \(\mathrm{Cl^{-}}\) are required.
3. Use the given amount of \(\mathrm{Mg^{2+}}\) ions, which is 0.25 moles, and multiply by the mole ratio of \(\mathrm{Cl^{-}}\) to \(\mathrm{Mg^{2+}}\) to find the moles of \(\mathrm{Cl^{-}}\) needed: \$0.25 \text{ moles } \times 2 = 0.50 \text{ moles}$.
4. Interpret the result: 0.50 moles of \(\mathrm{Cl^{-}}\) ions are required to completely react with 0.25 moles of \(\mathrm{Mg^{2+}}\) ions.
5. Confirm that this matches the stoichiometric requirements of the reaction and select the correct answer accordingly.