Problem: The "free-base" form of cocaine (C17H21NO4) and its protonated hydrochloride form (C17H22ClNO4) 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.The hydrochloride form of cocaine has a solubility of 1.00 g in 0.400 mL water. Calculate the molarity of a saturated solution of the hydrochloride form of cocaine in water.

🤓 Based on our data, we think this question is relevant for Professor Widdifield's class at OAKLAND.

FREE Expert Solution

Recall that molarity is the ratio of the moles of solute and the volume of solution (in liters). In other words:


molarity (M)=moles soluteL solution



The moles of cocaine hydrochloride is:

molar mass C17H22ClNO4 = 339.806 g/mol

moles C17H22ClNO4=1.00 g×1 mol339.806 g

moles C17H22ClNO4 = 2.9428x10-3 mol



Calculate the volume of the solution: 1 mL = 10-3 L


volume=0.400 mL×10-3 L1 mL

volume = 4.0x10-4 L



We can now calculate for molarity:

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Problem Details

The "free-base" form of cocaine (C17H21NO4) and its protonated hydrochloride form (C17H22ClNO4) 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.

Cocaine is a seven membered ring with carbon as all of its vertices and both the upper left and lower left vertices single bonded to the same N; that N is single bonded to CH3. The upper right vertex is single bonded to COOCH3, and the right point is single bonded to an O that is single bonded to a CO attached to the lower left vertex of a benzene ring with its points arranged vertically. Cocaine is added to HCl to produce cocaine hydrochloride. Cocaine hydrochloride has the same structure as cocaine, except the N attached to the seven-membered ring is now N+ and is also single bonded to the H from HCl. Cl- is nearby.


The hydrochloride form of cocaine has a solubility of 1.00 g in 0.400 mL water. Calculate the molarity of a saturated solution of the hydrochloride form of cocaine in water.

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Based on our data, we think this problem is relevant for Professor Widdifield's class at OAKLAND.