9769
On the azo / hydrazo equilibrium in Sudan I azo dye derivatives .
 Chemical: azo; Chemical: hydrazo; Chemical: Sudan I; Chemical: azo
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: azo; Chemical: hydrazo; Chemical: Sudan I; Chemical: azo