State what is meant by an ideal gas.
Two cylinders A and B are connected by a tube of negligible volume, as shown in the figure below.
Initially, tap T is closed. The cylinders contain an ideal gas at different pressures.
Cylinder A has a constant volume of 
and contains gas at pressure 
and temperature 
. Show that cylinder A contains 
of gas.
Cylinder B has a constant volume of 
and contains 
of gas. When tap T is opened, the pressure of the gas in both cylinders is 
. No thermal energy enters or leaves the gas. Determine the final temperature of the gas.
By reference to work done and change in internal energy, suggest why the temperature of the gas in cylinder A has changed.
