Physics·Heat·Gas/Principles and Exploration
Gas pressure and volume — principles and investigation
Examine the gas pressure and volume of blocking the syringe inlet and pressing the piston. Fix the amount and temperature of the gas and record the change in pressure by only changing the volume. The inverse relationship of Boyle's law cannot be applied when the temperature or amount of gas is also changed.
How does it work?
In an isothermal process, pressure is inversely proportional to volume.
PV = nRT · T, if n is the same, PV is constant
Try this investigation
- Fix the temperature and change the volume. Pressure is calculated using the ideal gas equation. The moving dots are illustrations illustrating the motion of the gas, not the actual number of molecules or collision statistics.
- Press the standard conditions button, run it, and record each measurement value.
- If you change the amount of gas or temperature, the PV value also changes. We need to compare points with the same n·T.
Interpreting your results
What does the P-1/V graph look like when the temperature and amount of gas are the same?
Since P = nRT × (1/V), it is a straight line with a slope of nRT.
Assumptions and limitations
It is an ideal gas model in equilibrium. The piston is a tool that selects the state, and heating, friction, and intermolecular forces during compression are omitted. The dots are for illustration purposes only and are not used in pressure calculations. Use R=8.314462618 kPa·L/(mol·K).