What is a statement of the second law of thermodynamics?

Answer 1

Every reaction in the universe increases the disorder, or entropy, of the universe. This is because energy that goes into a reaction is usable energy, but after the reaction, the energy is not usable anymore.

Answer 2

The second law of thermodynamics states that mechanical work can be derived from a body only when that body interacts with another at a lower temperature.

---------------------------------------------

Answer The laws of thermodynamics have been found to have broader application than the field of thermodynamics. The second law can be stated as: The entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium.- Where entropy can be regarded as randomness or 'chaos'. This application of the second law applies to closed systems, and therefore does not apply to systems that exchange information or energy outside the system. It does not apply to living organisms, as they are not closed systems. The second law applies to macroscopic systems, and therefore does not always apply to microscopic particles. In the field of thermodynamics, it can be stated from the above that the entropy of a thermally isolated macroscopic system never decreases.

---------------------------------------------

The second law of thermodynamics is:

No process is possible whose sole result is the transfer of heat from a body of lower temperature to a body of higher temperature.

==========

From the pre-merge Expert answer by Hilmar Zonneveld... Confidence votes 60.8K There are many different ways the Second Law can be expressed, all of them equivalent. Here are some:

* Useful energy can be converted to unusable energy - not the other way round.

* In a closed system, a property called "entropy" can only increase over time - it can never decrease.

* The efficiency of a heat engine can never be greater than that of the theoretical Carnot engine.

Answer 3

Law of thermodynamics deals with the heat energy involved in a reaction. According to second law of thermodynamics, the energy system tries to increase the entropy. The entropy is a measure of chaos of molecules.

Answer 4

There are two laws of thermodynamics:

1: energy cannot be created or destroyed but can be transferred from one form to another. For example, potential energy to kinetic energy

2: the total entropy of the universe is constantly increasing.

In Biology the second law shows up in the requirement of organisms to consume outside energy to survive and give off energy as they convert that energy to usable form. Animals have to eat. Plants usually need light to power photosynthesis. Decaying matter in compost heaps gives off heat as the decomposition takes place. Pretty much all biological processes are exothermic. These are all manifestations of the second law in action.

Answer 5

It is expressed in several ways which happen to be equivalent; for example, that entropy in an "isolated system" can increase but not decrease, and that there are processes in the Universe that are irreversible (with respect to energy).

Answer 6

The Kelvin-Planck Statement of the Second Law of Thermodynamics states that it is impossible to

create a Heat Engine that absorbs an amount of heat, QA , and yields net work, Wnet, equal to the amount of heat absorbed. All Heat Engines must disperse some portion of the heat absorbed (the dispersed energy cannot therefore be turned into work). In other words, all Heat Engines have a thermal efficiency less than 100 percent.

The Claussius Statement of the Second Law of Thermodynamics state that the spontaneous flow of heat is from high temperature region to low temperature region. Movement of heat from low temperature region to a high temperature region requires a work input by way of what is called a Heat Pump. The Heat Pump pumps heat up a temperature gradient.

Answer 7

There are many different ways the Second Law can be expressed, all of them equivalent. Here are some:* Useful energy can be converted to unusable energy - not the other way round.

* In a closed system, a property called "entropy" can only increase over time - it can never decrease.

* The efficiency of a heat engine can never be greater than that of the theoretical Carnot engine.

Answer 8

There are several correct (and equivalent!) statements; for example:* No heat engine can get more energy, out of a heat bath, than the theoretical Carnot engine.

* There is a quantity called entropy, which can only increase over time. It can't decrease.

* The amount of usable energy in a closed system will decrease over time.

Answer 9

There are several ways to state the Second Law; they have been shown to be equivalent.I think the most intuitive one is in terms of energy. The FIRST Law of Thermodynamics states that energy can't be created or destroyed; however, due to the SECOND Law, useful energy is continuously being converted into unusable energy, i.e., "used up" or "wasted". This is irreversible.

For additional ways to state the Second Law, check the Wikipedia articles on "Second Law of Thermodynamics", on "Entropy", and perhaps even on "Ultimate Fate of the Universe", if you are interested in long-term effects of the Second Law.

Answer 10

It states that in a closed system, the entropy of a system does not decrease.