Which of the following refrigerants is classified as an HFC?

Refrigerants are classified into different categories based on their chemical composition, and HFCs, or hydrofluorocarbons, are a significant group. R-134a is a well-known HFC, characterized by its chemical formula of C2H2F4.

HFCs like R-134a are commonly used in refrigeration and air conditioning systems due to their lower ozone depletion potential compared to older refrigerants like CFCs (chlorofluorocarbons). They also have better thermodynamic properties, making them suitable for use in a wide range of applications. R-134a specifically is widely adopted as a replacement for R-12, reflecting a shift in industry standards toward more environmentally friendly options.

Other options, such as R-123, belong to the HCFC category, which stands for hydrochlorofluorocarbons. R-717 is ammonia, which is categorized as a natural refrigerant or an inorganic substance rather than an HFC. Lastly, HCs refer to hydrocarbons that are also not HFCs but are sometimes used in specific applications due to their natural origin and lower environmental impact. Thus, R-134a stands out as the only refrigerant in the provided list that is identified