Question 1
Paper 2Hard10 marksA fixed amount of gas is measured in a cylinder with a movable piston. Figure 1 shows the measured pressure–volume states of the gas at two temperatures. The temperatures are in kelvin. is a further state of the same gas, at an unrecorded temperature. No curves have been fitted to the measurements.
Describe the pressure–volume relationship indicated by the measurements.
For the measurements at calculate at each temperature. Give an appropriate unit.
A fixed amount of gas changes from state 1 to state 2 Using the empirical pressure–temperature law at constant volume and Boyle’s law at constant temperature, derive a relation between these two states. Temperatures are in kelvin.
A controller is expected to switch when the gas reaches Use state and both calibration results from part (b) to estimate the temperature at and decide whether the controller’s reported temperature is consistent with the measurements. Show your working.