Precipitate silver$($I$)$ chloride in two testing tubes by addition of silver$($I$)$ nitrate solution to the same volume of sodium chloride solution. Then we added to the first testing tube three volumes of $1$ M solution of ammonia. In the second one dissolve precipitated silver$($I$)$ chloride by addition three volumes of $1$ M solution of sodium thiosulfate. To both testing tubes a few drops of potassium iodide were added. a$)$Give chemical equation for reaction undergoing between silver$($I$)$ chloride and ammonia and sodium thiosulfate $($coordination number for Ag$+=2)$ which lead to formation of suitable complexes; give dissociation equations. Write chemical equation for precipitation of silver$($I$)$ iodide in one of the testing tubes; explain observed phenomena taking into account dissociation equation of suitable complex ion and solubility product. b$)$Why in the second testing tube does a solid not precipitate. c$)$Which complex is more stable? Write equilibrium expressions for both complexes. Which of them is smaller?