Objective 06: Entropy

Question 1

Entropy

Answer 1

The energy within a substance at any given condition or state that is NOT available to do work or to be transferred

Question 2

What is the relationship between Energy and Entropy?

Answer 2

Proportional

Question 3

What is the magnitude of heat transferred into or out of a substance equal to?

Answer 3

An average temperature that lies between the initial and final temperatures

Question 4

What is the change in entropy during a thermodynamic process a function of?

Answer 4

1. The heat transferred

2. The absolute temperature(s) at which it transfers

Question 5

During a heat transfer, why does the heat source experience less entropy change than the heat sink?

Answer 5

The heat source has a higher mean temperature than the heat sink

Question 6

During a heat transfer, is the total heat given off by the source equal to the total heat received by the sink?

Answer 6

Yes

Question 7

What is the universal principle regarding Entropy?

Answer 7

Within a closed thermodynamic system, the net entropy always increases

Question 8

What is the consequence of Net Entropy always increasing?

Answer 8

The potential for a quantity of energy to do work decreases whenever it is transferred or whenever it is converted from one form to another. Once converted, energy loses the ability on its own (i.e. without work being done on it) to be converted back to its original, more energy intense state.

Question 9

Does dryness fraction need to be taken into account when calculating Entropy for wet steam?

Answer 9

Yes