write the net ionic and formula unit equation for the reaction between mercury(ii) nitrate and potassium iodide (look up the solubility rules for iodide!). i) the supernatant liquid was collected from the above precipitation reaction when mercury(ii) nitrate was added to the supernatant solution, no further precipitation occurred. when potassium iodide was added to the supernatant solution, a precipitate formed. which reagent is the limiting reagent?