need chemistry help

Question

in the balanced chemical equation below, how many grams of lithium carbonate are produced from 0.19 moles of lithium phosphate and excess iron(ll) carbonate?

3FeCO3+Li3PO4 —> Li2CO3 + Fe3(PO4)

Answer 1

To answer this question the first step is to figure out how much Li we have as we have excess carbonate. We have .19 moles of Li3PO4, but each unit of that compound has three equivalents of lithium so there is .57 moles of Li+. Li2CO3 requires 2 Li+ per compound so we divide the amount of Li in half to find out how many moles of Li2CO3 we can make. That would be .285 mols. To answer the question all we need to do now is to multiply the number of mols by the molecular mass (g/mol) of Li2CO3 or 73.89 g/mol. The reaction would make 21 g of Li2CO3 to the correct number of significant figures. (There were only two in the value given)