What volume (in L) of 1.10 M FeCl_3 solution is required to obtain 0.700 moles of Cl^- ions?

• A. 0.212 L
• B. 0.318 L
• C. 0.636 L
• D. 0.700 L

Answer: (A)

Verified step by step guidance

1. Identify the dissociation of FeCl_3 in water. FeCl_3 dissociates into one Fe^{3+} ion and three Cl^- ions, so each mole of FeCl_3 produces 3 moles of Cl^- ions.
2. Write the relationship between moles of FeCl_3 and moles of Cl^- ions: \(\text{moles of Cl}^- = 3 \times \text{moles of FeCl}_3\).
3. Calculate the moles of FeCl_3 needed to get 0.700 moles of Cl^- ions by rearranging the equation: \(\text{moles of FeCl}_3 = \frac{0.700}{3}\).
4. Use the molarity definition to relate moles and volume: \(M = \frac{\text{moles of solute}}{\text{volume in liters}}\); rearranged to find volume: \(V = \frac{\text{moles of FeCl}_3}{M}\).
5. Substitute the values for moles of FeCl_3 and molarity (1.10 M) into the volume equation to find the required volume of FeCl_3 solution.