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?

Aerosols are important components of the atmosphere. Does the presence of aerosols in the atmosphere increase or decrease the amount of sunlight that arrives at the Earth's surface, compared to an 'aerosol-free' atmosphere? Explain your reasoning.

The 'free-base' form of cocaine (C₁₇H₂₁NO₄) and its protonated hydrochloride form (C₁₇H₂₁NO₄) 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 (e) How many mL of a concentrated 18.0 M HCl aqueous solution would it take to convert 1.00 kilograms (a 'kilo') of the free-base form of cocaine into its hydrochloride form?

A supersaturated solution of sucrose (C₁₂H₂₂O₁₁) is made by dissolving sucrose in hot water and slowly letting the solution cool to room temperature. After a long time, the excess sucrose crystallizes out of the solution. Indicate whether each of the following statements is true or false: (b) After the excess sucrose has crystallized out, the system is now unstable and is not in equilibrium.

Most fish need at least 4 ppm dissolved O₂ in water for survival. (a) What is this concentration in mol/L?