19806
All investigations were completed by the ultrasound absorption coefficient measurements in 1 - ethyl - and 1 - octyl - 3 - methylimidazolium bis [ ( trifluoromethyl ) sulfonyl ] imide as a function of frequency from 10 to 300 MHz at temperatures 293 . 15 - 298 . 15 K .
 Chemical: 1 - ethyl - and 1 - octyl - 3 - methylimidazolium bis [ ( trifluoromethyl ) sulfonyl ] imide
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: 1 - ethyl - and 1 - octyl - 3 - methylimidazolium bis [ ( trifluoromethyl ) sulfonyl ] imide