Azo dyes are organic compounds, which are largely used in the treatment of textiles andleather products, as well as in food. Phenylamine, C6H5NH2, can be used in the manufacture of azo dyes.
The manufacturing process is outlined below.
Step 1
Phenylamine is dissolved in HCl to produce a diazonium salt. A diazonium salt contains two nitrogen atoms joined together by a triple bond. The reaction for this process is as follows:
C6H5NH2 + HCl + HNO2 → C6H5N2+Cl- + 2H2O
Step 2
This solution is then slowly added to an alkaline solution of a phenol coupling agent to form the dye.
i)
The diazonium salt, C6H5N2+Cl-, is an unstable compound. Suggest a condition that could be added to ensure that the salt would not break down during the reaction.
ii)
Draw the structure of the diazonium salt formed in Step 1, showing the displayed formula of the nitrogen containing group.