The “free-base” form of cocaine (C₁₇H₂₁NO₄) and its protonated hydrochloride form (C₁₇H₂₂ClO₄) are shown below; the free-base form can be converted to the hydrochloride form with one equivalent of HCl. For clarity, not all the carbon and hydrogen atoms are shown; each vertex represents a carbon atom with the appropriate number of hydrogen atoms so that each carbon makes four bonds to other atoms.

a. Which form of cocaine, the free base or the hydrochloride, is relatively water-soluble?