If you have 9 moles of CaCl2 and an excess of Na3PO4, how many moles of Ca3(PO4)2 can be formed according to the balanced equation: 3 CaCl2 + 2 Na3PO4 → Ca3(PO4)2 + 6 NaCl?

• A. 3 moles
• B. 2 moles
• C. 4.5 moles
• D. 6 moles

Answer: (A)

Verified step by step guidance

1. Identify the balanced chemical equation: 3 CaCl2 + 2 Na3PO4 → Ca3(PO4)2 + 6 NaCl.
2. Determine the mole ratio between CaCl2 and Ca3(PO4)2 from the balanced equation. For every 3 moles of CaCl2, 1 mole of Ca3(PO4)2 is formed.
3. Since Na3PO4 is in excess, CaCl2 is the limiting reactant, so the amount of Ca3(PO4)2 formed depends on the moles of CaCl2.
4. Use the mole ratio to calculate the moles of Ca3(PO4)2 formed: multiply the moles of CaCl2 (9 moles) by the ratio (1 mole Ca3(PO4)2 / 3 moles CaCl2).
5. The result from this calculation gives the moles of Ca3(PO4)2 that can be formed.