Control test tube A contains 1mL each of solutions of BiCl3 and NH3. Test tube B contains 1mL each of solutions of BiCl3 and NH3 and 1g of NH4Cl. A clear gelatinous precipitate of Bi(OH)3 forms in test tube A while no ppt. forms in test tube B. The appearances of test tubes A and B are due to the interplay between the ammonia and bismuth hydroxide equilibria. NH3(aq) + H2O(l) <--> NH4+(aq) + OH-(aq) Bi+3(aq) + 3OH-(aq) <--> Bi(OH)3(s) What common ion is present in test tube B? How does addition of this common ion affect the ammonia and hismuth hydroxide equilibria? Explain the results (difference in appearance between test tubes A and B) in terms of the common ion effect. What will happen in test tube A if concentrated HCl is slowly added? Explain.