91. Solving a chemistry problem

a) The colloidal solution was obtained by the condensation method in accordance with the equation:
2AgNO3(excess) Na2CO3 = Ag2CO3 2NaNO3.
Write the sol formula.
Which ions will be potential-determining? Indicate the charge of colloidal particles. In what direction will they move in an electric field (towards the cathode or towards the anode)?
b) Write the equation for obtaining the negative sol of bismuth hydroxide (Bi(OH)3). Suggest an electrolyte for its destruction with the lowest coagulation threshold among the proposed ones: K2SO4, Cu(NO3)2, FeCl3, Na3PO4, FeSO4.