posted by Dora .
2. Why doesn’t the neutral organic compound (Flourene) dissolve in 1.5 M sodium hydroxide solution?
Did you mean fluorene? Fluorene is a hydrocarbon, much like naphthalene or anthracene. Materials that are soluble in NaOH solution usually are soluble in water alone or they are acidic in nature. I'm not an organic chemist but I wouldn't expect fluorene to be soluble in NaOH.