The limiting reagent is PbCO3
Explanation
limiting reagent definition;
is the reagent that is totally consumed when a chemical reaction occurs completely
write a balanced chemical equation for the reaction
that is
PbCO3 +2 Ki → PbI2 + K2CO3
from the equation above the b 1 mole of PbCO3 react with 2 moles of Ki
therefore PbCO3 is the limiting reagent since has less number of moles