) What purpose does sodium nitrite and HCl serve during the formation of the diazonium salt? What is generated by mixing those two compounds? Where does the second nitrogen on the R-N2 moiety come from? 2) What does the sodium dithionite do to indigo? Why is this process of exposing the indigo to sodium dithionite necessary to dye fabric? 3) During the reaction between sodium dithionite and indigo, a blue film is observed on the surface of the solution and on the walls of the flask. What is this film, and why does the film not disappear and form a homogeneous solution? If you were to perform this reaction under N2 gas, would you expect to observe this film and why? What about if you were to perform this experiment in a regular beaker on a hot plate? Would this ameliorate the issue?