Introduction

Hey, teenagers are still growing, and they are often hungry. So it makes sense that the refrigerator door might be the first door you open in the morning and the last door you close at night. At one time, homes relied on an icebox and daily deliveries of ice to refrigerate food. Today, refrigeration is a heavily relied-upon technology.

Did you know that the technology used to operate a modern refrigerator relies on the energy change that occurs when certain molecules undergo a phase change? This technology goes back to the mid-1700s. Unfortunately, the first refrigerants (like diethyl ether and ammonia) posed a health risk and were not the safest substances to use.

In a quest to find safer refrigerants, a class of organic compounds called chlorofluorocarbons (CFCs) were developed and tested. The first CFCs were found to have chemical and physical properties suitable for use in refrigeration systems, and they were non-toxic. As a result, CFCs were quickly adopted for use as refrigerants.

Consider the structural formulae for two CFCs:

 

A diagram shows the structural formulae for two CFCs, dichlorodifluoromethane and 2-chloro-1,1,1,2-tetrafluoroethane.

 

CFCs and other organic molecules can contain halogens. In Lesson 2 you will learn about organic halides, including how they are made and used. Organic halides are halogen-containing organic molecules.

Consider the following questions as you complete Lesson 2:

  • What are organic halides?
  • In what reactions are organic halides involved?

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