Congo Red is an azo dye commonly used in the textile industry. Consider its complete synthesis, shown in Figure 1.3, to respond to Questions 3 to 6 : 3. The nitration reaction used to convert benzene (1) to nitrobenzene ( 2) is an example of what type of reaction? 4. If 5.0g of nitrobenzene (2) is converted to hydrazobenzene (3) with 100% yield, what mass of hydrazobenzene is obtained (in grams)? MW nitrobenzene =123.11g/mol, MW hydrazobenzene =184.24g/mol 21 5. What is the minimum number of molar equivalents of sodium naphthionate ( 6) needed to react with the biphenyl bis-diazonium chloride (5) to produce Congo Red? 6. Identify the nucleophile and the electrophile in the diazonium coupling reaction between sodium naphthionate (6) and biphenyl bis-diazonium chloride (5). H2SO4HNO3 1 2 Figure 1.3 The complete synthesis of Congo Red from benzene. Figure generated using ChemDraw Professional 15.1