Using a single reagent and only reaction chemistry that was part of this experiemnt, how could you distinguish between the following pair of substances contained in seperate test tubes? Explain in word how you could tell, and give the net ionic equaion for any reaction that occurs in the test.

a. Hg2(NO3)2 and Mg(NO3)2 solution Reagent

b. Hg2Cl2 and AgCL solid Reagent

c. Na2CrO4 and HCl solution Reagent