Hey guys, chemistry noob here. Can you help me with the questions in pic related and explain the answers to me, give me the basic idea of common ion effect on solubility?
Am I right for the first question?: The concentration of Pb2+ goes up, Cl- goes down and equilibrium shifts to the reactants and lowers the solubility.
>>7804885
Yes, you are correct in your reasoning.
Ions which do not participate in the reaction (e.g. any of the other ones except Cl- in NaCl) do not affect the equilibrium.
>>7804891
But am I correct to assume that adding H2O will increase solubility? Also what happens to the solubility when adding compounds that don't share a common ion?
>>7804897
Since it's aqueous, and solubility product is determined by molarity, not absolute mole content, yes, adding more H2O will increase the amount of Pb2+ in the solution, but the concentration itself will not increase. Adding compounds that do not share a common ion will not affect concentration either, as the reaction quotient will not change.
Also for question e) Br will form a precipitate with Pb2+, what effect will it have on the concentration of Pb2+, Cl-, PbCl2, and what will happen to the solubility?
>>7804921
>concentration
sorry I meant amount
>>7804921
Oh, since it forms a precipitate, it will change the concentration- meaning it will increase the solubility of PbCl2 (insoluble solids are not included in the reaction quotient)
>>7804932
Hmm so what happens to the concentrations? and why would the solubility go up if there is a precipitate?
>>7805005
If there's a precipitate, products are removed. This means that the reaction quotient is smaller than the equilibrium constant, resulting in more reactants reacting. The concentrations will ultimately stabilize at equilibrium, but more of the reactants will dissolve.
