0.044 0 mol 0.044 0 mol H2 O2 Figure P21.24

A 0.50-kg piece of aluminum at 250 °C is dropped into 1.0 kg of water at 20 °C . After equilibrium is reached, what is the net entropy change of the system?

A large factory furnace maintained at 170 ∘C at its outer surface is wrapped in an insulating blanket of thermal conductivity 5.50×10−2 W/(m⋅K) which is thick enough that the outer surface of the insulation is at 43.0 ∘C while heat escapes from the furnace at a steady rate of 140 W for each square meter of surface area. By how much does each square meter of the furnace change the entropy of the factory every second?

A box contains 100 gas molecules all released on the left side of the box. What is the initial entropy of all the gas molecules on one side? You can calculate the number of microstates (left/right distribution of molecules) possible by the equation W = N! / ( nL! * nR!,) where N is the total number of molecules and nL is the number on the left and nR is the number on the right. What is the entropy of the most disorganized distribution of gas molecules?

A rigid box contains 0.9 mol of an ideal monoatomic gas. Heat is added to the gas and its temperature changes from 183 K to 295 K. If this is a reversible process, what is the change in entropy of the gas in J/K?

A 100-lbm block of a solid material whose specific heat is 0.5 Btu/lbm·R is at 80°F. It is heated with 10 lbm of saturated water vapor that has a constant pressure of 20 psia. Determine the final temperature of the block and water, and the entropy change of the entire system. Is this process possible? Why?