What is the initial boiling point of the substance discussed?

The initial boiling point of a substance is a critical property, as it indicates the temperature at which the substance transitions from a liquid to a gas under standard atmospheric conditions. In this context, the correct choice, which states the initial boiling point as -28°F, highlights that the substance has a low boiling point, characteristic of certain refrigerants and volatile substances.

A low boiling point means that at even relatively low ambient temperatures, the substance would readily vaporize, which is a desirable property for refrigerants used in industrial refrigeration systems. The ability to vaporize efficiently allows these systems to effectively absorb heat from the environment, thereby facilitating cooling.

In contrast, choices that suggest boiling points of -33.4°C, 0°F, or 32°F do not match the characteristics of some common refrigerants used in industrial settings, which often have low boiling points to ensure efficient heat absorption and vaporization in cooling applications. Understanding the significance of boiling points helps operators in selecting the appropriate refrigerants for specific applications, ensuring efficient and effective refrigeration cycles.