What is the mixture known as "crack" primarily composed of?

The mixture known as "crack" is primarily composed of cocaine mixed with baking soda. This combination undergoes a process of heating and cooling that creates solid 'rocks' or crystals of crack cocaine, which can be smoked for a rapid and intense high.

In this process, baking soda acts as a base that facilitates the conversion of cocaine hydrochloride into freebase cocaine, which is more potent and suitable for smoking. This method of processing enhances the drug's bioavailability and alters its pharmacological effects, making it a popular choice among users looking for a quick and strong euphoric experience.

The other options do not accurately represent the composition of crack cocaine. Water, sugar, and salt do not contribute to the typical chemical transformations that lead to the creation of crack from cocaine. Understanding these details is crucial for grasping the physical and chemical properties of various forms of cocaine and their associated health risks.