Please help!! How many moles of sodium carbonate (Na2CO3) are required to precipitate the calcium ion from 803.1 mL of a 0.35 M CaCl2 solution?

Explanation:

Hello,

In this case, the undergoing chemical reaction is:

Hence, given the solution of calcium chloride, we can compute its reacting moles:

Thus, by knowing there is a 1:1 molar ratio between sodium carbonate and calcium chloride, we can easily compute the moles of sodium carbonate needed for a complete precipitation as shown below:

Best regards.