Which of the following is NOT a hydrophobic substance?
A - C3H8 (propane)
B - C2H6 (ethane)
C - CH3CO2H (acetic acid)
D - C6H6 (benzene)
E - CH4 (methane)
Answer: C - CH3CO2H (acetic acid)
Acetic acid is polar, like water meaning it is not hydrophobic. HYDROPHILIC are molecules that are polar and are able to form hydrogen bonds with water molecules.