A cylinder contains mol of helium at °C. What accounts for the difference between your answers to parts (a) and (b)? In which case is more heat required? What becomes of the additional heat?
(a) How much heat is needed to raise the temperature to °C while keeping the volume constant? Draw a -diagram for this process.
(b) If instead the pressure of the helium is kept constant, how much heat is needed to raise the temperature from °C to °C? Draw a -diagram for this process.