If all of the hydrogen atoms have been replaced in the base molecule by chlorine and fluorine, the refrigerant is said to be?

When all of the hydrogen atoms in a base molecule are replaced by halogens such as chlorine and fluorine, the refrigerant is classified as fully halogenated. This designation indicates that the molecule has undergone complete substitution of hydrogen, resulting in a chemical species that is often more stable and less flammable compared to its partially halogenated counterparts.

Fully halogenated compounds are important in refrigeration because they typically demonstrate desirable properties such as low toxicity and efficient heat transfer. Additionally, they tend to have lower ozone depletion potential compared to their partially halogenated variants. Understanding the degree of halogenation is crucial for safety and environmental considerations in the use of refrigerants.

The other options point to various levels of halogenation, with partially halogenated referring to compounds where not all hydrogen has been replaced, and hydrochlorofluorocarbon indicating a specific type of partially halogenated refrigerant. Azeotropic pertains to mixtures of substances that exhibit constant boiling behavior and is not directly related to the halogenation of a compound.