Final answer:
The refrigerant used in cars manufactured in 1993 and newer is R-134a, a hydrofluorocarbon that replaced the ozone-depleting R-12. Freon-12 (R-12) is a gas at room temperature. Other mentioned HCFCs and carbon tetrachloride are different substances used in various industrial applications.
Step-by-step explanation:
The refrigerant used in cars manufactured in 1993 and newer is typically R-134a. Before 1993, R-12 was the common refrigerant but it was phased out because it contributed to damage of the Earth's ozone layer. R-134a, a type of hydrofluorocarbon (HFC), was one of the main replacements for R-12 because it has less impact on the ozone layer and is not a chlorofluorocarbon (CFC). Therefore, option 2) R-134a is the correct answer for the refrigerant used in cars manufactured in 1993 and newer.
Answering Exercise 1.2.1, Freon-12 is a gas at room temperature, since its boiling point is -29.8°C and room temperature is usually around 25°C.
To address other substances mentioned: hydrochlorofluorocarbon-22 (HCFC-22), hydrochlorofluorocarbon-123 (HCFC-123), hydrochlorofluorocarbon-124 (HCFC-124), and carbon tetrachloride are all either refrigerants, solvents, or used in chemical productions, but they are not the refrigerant option for cars manufactured after 1992.