Question: one mole of an ideal gas is enclosed in a...
One mole of an ideal gas is enclosed in a cylinder with
diathermal (i.e. thermally conducting) walls. On one end of the
cylinder is a frictionless movable piston with a weight on top. The
weight is insufficient to balance the pressure of the gas; however,
the piston is locked in place so that the piston cannot move
initially. The entire assembly of cylinder + weight is immersed in
a large water bath, the purpose of which is to keep the temperature
of the gas constant at 300 K.
The pressure due to the weight is 1 atm. Consider the following cyclic process. At time zero, the lock on the piston is removed. Because the weight cannot balance the gas pressure, the gas is allowed to expand irreversibly from 1 L to 2 L. By sequentially placing grains of sand on the piston one by one, the gas is then reversibly compressed back to its original volume. Calculate the total heat that flows during the cycle.