Guaifenesin Isolation. Questions: G1. Define the terms hydrophilic substance and hydrophobic substance. G2. What type of substance is hexane? G3. What type of solutions are found in living tissues, Aqueous or Organic? G4. The inactive ingredients in tablets are often present to enhance solubility of the active ingredient guaifenesin. What types of solvent should be avoided if the goal is to keep the inactive ingredients in undissolved? G5. If guaifenesin is soluble both in hexane and in stomach, cells, circulatory system, what term(s) describe guaifenesin? G6. What solvent should be used to wet the filter paper for gravity filtration and for vacuum filtration