3. (a) What is the evidence for a shift in equilibrium when silver nitrate is added to the stock solution? (The formation of a precipitate is not the evidence since the precipi- tate is not one of the substances in the equilibrium.) The colon changed to Yellow. dcloudy (b) The change in concentration of which ion in the equilibrium caused this equilibrium shift? (c) Write a net ionic equation to illustrate how this concentration change occurred. (d) When the mixture in C.4 was divided and further tested, what evidence showed that the mixture still contained Fe3+ ions in solution?