Chapter 6, Problem 6.3E

Define the following question

The entropy change between two specified states is the same whether the process is reversible or irreversible.

Give an example of Energy and entropy balances for a system.

A 60-lb aluminum bar, initially at T3 = 150°F, is placed in a tank together with 190 lb of liquid water, initially at Tw = 70°F, and allowed to achieve thermal equilibrium. The aluminum bar and water can be modeled as incompressible with specific heats c, = 0.216 Btu/lb-°R and Cw = 0.998 Btu/lb-°R, respectively. Consider the aluminum bar and water as the system and ignore heat transfer between the system and its surroundings. Determine the final temperature Tr, in °F, and the amount of entropy produced within the tank, in Btu/°R.

For any irreversible process the net entropy change is Zero positive O negative O infinite O unity O

Answer the following true or false. Explain. (a) A process that violates the second law of thermodynamics violates the first law of thermidynamics. (b) When a net amount of work is done on a closed system undergoing an internally reversible process, a net heat transfer of energy from the system also occurs. (c) One corollary of the second law of thermodynamics states that the change in entropy of a closed system must be greater than zero or equal to zero. (d) A closed system can experience an increase in entropy only when irreversibilities are present within the system during the process. (e) Entropy is produced in every internally reversible process of a closed system. (f) In an adiabatic and internally reversible process of  a closed system, the entropy remains constant. (g) The energy of an isolated system must remain constant, but the entropy can only decrease.

The entropy of an ideal gas depends on both T and P. The function s° represents only the temperature-dependent part of entropy.

The rate of entropy transfer associated with heat transfer from a closed system operating at steady state to its surroundings must be equal to the rate of entropy production due to irreversibilities within the system. O True O False eTextbook and Media Save for Later

A 60-lb aluminum bar, initially at T₂ = 150°F, is placed in a tank together with 190 lb of liquid water, initially at Tw= 70°F, and allowed to achieve thermal equilibrium. The aluminum bar and water can be modeled as incompressible with specific heats c₂ = 0.216 Btu/lb.ºR and cw = 0.998 Btu/lb.°R, respectively. Consider the aluminum bar and water as the system and ignore heat transfer between the system and its surroundings. Determine the final temperature Tf, in °F, and the amount of entropy produced within the tank, in Btu/°R.