The observations for each test are:
A: Br$_2$ water test indicates unsaturation (reddish orange color disappears).
B: Ceric ammonium nitrate test detects alcohols (red color appears).
C: Ferric chloride test detects phenols (blue, green, violet, or red color appears).
D: 2,4-DNP test detects aldehydes/ketones (yellow-orange precipitate).
All the letters of the word "GTWENTY" are written in all possible ways with or without meaning, and these words are arranged as in a dictionary. The serial number of the word "GTWENTY" is: