An experiment is being carried out by two students. Anne tests the filtrate of a salt mixture with
CaCl 2 in one test tube, while Phil tests the same filtrate with K 2 C 2 O 4 in a second test tube.
Phil observes a white precipitate, while Anne does not. Which reactant is limiting in the original
salt mixture? Explain.
Solution
Anne test : does not form precipitate
The solution is unsaturated. Untill excess of CaCl2 is added, no precipitate would form here.
Limiting reactant = CaCl2
Phil test : white precipitate formed
The solution is saturated. All of ion in solution has reacted with added reagent. Reagent is in
excess.
Limiting reactant : Filtrate solution