CP units are typically which of the following?

• A. Btu/lb·°F and J/(kg·K)
• B. W/(m·K)
• C. Pa
• D. J/(kg·K)

Answer: (A)

CP refers to specific heat capacity, which is the amount of energy needed to raise the temperature of a unit mass by one degree. That means its units are energy per mass per temperature. In English engineering units, this is Btu per pound per degree Fahrenheit; in SI, it is joules per kilogram per kelvin. That dual representation is why the option listing both Btu/lb·°F and J/(kg·K) is the best choice. The other options describe different properties—W/(m·K) is thermal conductivity, and Pa is pressure—and, while J/(kg·K) is a valid SI unit for cp, the combined units in the chosen option best reflect the common ways cp is expressed.