A rigid, thermally insulated container is divided into two equal-volume chambers by a thin removable partition. Chamber A initially contains 0.75mol of an ideal gas at 300K and 1.0×105Pa. Chamber B is a vacuum. At time t=0 the partition is suddenly removed, allowing the gas to expand freely and fill the entire container. The container walls are perfect thermal insulators, and the gas temperature remains at 300K throughout the process.
(a) Determine the ratio of the final volume of the gas to its initial volume.
(b) Calculate the change in entropy of the gas as it expands to fill the entire container.
(c) Explain, without numerical calculation, why no energy must be transferred to or from the gas for its entropy to increase in this process.