When a liquid is converted to a gas there is an increase in entropy

For each process, tell whether the entropy change of the system is positive or negative, (a) A glassblower heats glass (the system) to its softening temperature, (b) A teaspoon of sugar dissolves in a cup of coffee. (The system consists of both sugar and coffee.) (c) Calcium carbonate precipitates out of water in a cave to form stalactites and stalagmites. (Consider only the calcium carbonate to be the system.)

9.20 State the first law of thermodynamics briefly in your own words.

Coal is used as a fuel in some electric-generating plants. Coal is a complex material, but for simplicity we may consider it to be a form of carbon. The energy that can be derived from a fuel is sometimes compared with the enthalpy of the combustion reaction: C(s)+O2(g)CO2(g) Calculate the standard enthalpy change for this reaction at 25C. Actually, only a fraction of the heat from this reaction is available to produce electric energy. In electric generating plants, this reaction is used to generate heat for a steam engine, which turns the generator. Basically the steam engine is a type of heat engine in which steam enters the engine at high temperature (Th), work is done, and the steam then exits at a lower temperature (Tl). The maximum fraction, f, of heat available to produce useful energy depends on the difference between these temperatures (expressed in kelvins), f = (Th Tl)/Th. What is the maximum heat energy available for useful work from the combustion of 1.00 mol of C(s) to CO2(g)? (Assume the value of H calculated at 25C for the heat obtained in the generator.) It is possible to consider more efficient ways to obtain useful energy from a fuel. For example, methane can be burned in a fuel cell to generate electricity directly. The maximum useful energy obtained in these cases is the maximum work, which equals the free-energy change. Calculate the standard free-energy change for the combustion of 1.00 mol of C(s) to CO2(g). Compare this value with the maximum obtained with the heat engine described here.

For each process, tell whether the entropy change of the system is positive or negative. (a) A glassblower heats glass (the system) to its softening temperature. (b) A teaspoon of sugar dissolves in a cup of coffee. (The system consists of both sugar and coffee.) (c) Calcium carbonate precipitates out of water in a cave to form stalactites and stalagmites. (Consider only the calcium carbonate to be the system.)

What happens to the entropy of the universe during a spontaneous process?

Which contains greater entropy, a quantity of frozen benzene or the same quantity of liquid benzene at the same temperature? Explain in terms of the dispersal of energy in the substance.

A 5.33-g piece of Cu metal is heated to 99.7C in boiling water, then dropped into a calorimeter containing 99.53g of H2O at 22.6C. The calorimeter is sealed to the outside environment, and temperature equalizes. Cp[Cu(s)]=0.385J/gK, Cp[H2O]=4.18J/gK. a Discuss the process that occurs inside the calorimeter in terms of the zeroth and first laws of thermodynamics. b What is the final temperature inside the system? c What is the entropy change of the Cu(s)? dWhat is the entropy change of the H2O(l)? e What is the total entropy change in the system? f Discuss the process that occurs inside the calorimeter in terms of the second law thermodynamics. Do you expect it to be spontaneous?