\documentclass[12pt]{article} \usepackage{graphicx, multicol,wrapfig,exscale,epsfig,fancybox,fullpage,amsmath} \pagestyle{empty} \parindent=0pt \parskip=.1in \newcommand\hs{\hspace{6pt}} \begin{document} \centerline{\textbf{Ungraded Quiz}} \bigskip \noindent Consider the two processes described below. \paragraph{Process \#1} Five moles of an ideal gas are initially confined in a one-liter cylinder with a movable piston, at a temperature of 300~K. Slowly the gas expands against the movable piston, while the cylinder is in contact with a thermal reservoir at 300~K. The temperature of the gas remains constant at 300~K while the volume increases to two liters. \paragraph{Process \#2} A thin plastic sheet divides an insulated two-liter container in half. Five moles of the same ideal gas are confined to one half of the container, at a temperature of 300~K. The other half of the container is a vacuum. The plastic divider is suddenly removed and the gas expands to fill the container. Because it is a free expansion of an ideal gas (no work is done on or by the gas), the final temperature of the gas is also 300~K. \paragraph{Process \#3} The same cylinder as in process \#1 is thermally insulated and then allowed to slowly expand, starting at 300~K, to twice its original size (two liters). \begin{center} \includegraphics[width=\columnwidth]{eefree_expansionfig.png} \end{center} \begin{enumerate} \item Are $\Delta S_\text{isothermal}$, $\Delta S_\text{free}$ and $\Delta S_\text{adiabatic}$, the change in entropy of the gas for each process, positive, negative, or zero? Please explain your reasoning. \vfill \item Is $\Delta S_\text{isothermal}$ greater than, less than, or equal to $\Delta S_\text{free}$? How do each of these compare with $\Delta S_\text{adiabatic}$? Please explain. \vfill \item Are $\Delta S_\text{surr-isothermal}$, $\Delta S_\text{surr-free}$ and $\Delta S_\text{surr-adiab}$, the change in entropy of the surroundings for each process, positive, negative, or zero? Please explain. \vfill \end{enumerate} \vfill \leftline{\textit{by David Roundy}} \leftline{\copyright DATE David Roundy} \end{document}