What does the SI unit Pascal measure?

• A. Temperature in Celsius
• B. Duration of time
• C. Force exerted by a vapor on sealed walls
• D. Volume of gas in a container

Answer: (C)

The SI unit Pascal measures pressure, which is specifically defined as the force exerted per unit area. When dealing with gases, the Pascal quantifies how much force the vapor exerts against the walls of a sealed container. This relationship is crucial in fields like refrigeration and air conditioning, where understanding the pressure of refrigerants is essential to ensure proper system operation and safety.

For example, in an HVAC system, monitoring pressure levels helps in diagnosing potential issues and ensuring the system runs efficiently. Options related to temperature, duration, and volume do not pertain to pressure measurements and therefore do not accurately describe what the Pascal measures.