Question

To understand the meaning and applications of the second law of thermodynamics, to understand the meaning of entropy, and perform some basic calculations involving entropy changes. The first law of thermodynamics (which states that energy is conserved) does not specify the direction in which thermodynamic processes in nature can spontaneously occur. For example, imagine an object initially at rest suddenly taking off along a rough horizontal surface and speeding up (gaining kinetic energy) while cooling down (losing thermal energy). Although such a process would not violate conservation of energy, it is, of course, impossible and could never take place spontaneously. The second law of thermodynamics dictates which processes in nature may occur spontaneously and which ones may not. The second law can be stated in many ways, one of which uses the concept of entropy.

Answer 1

Answer:

The first law of thermodynamics is also known as the principle of conservation of energy. It states that if work is done on one system or it exchanges heat with another, the internal energy of the system will change.

The second law of thermodynamics marks the direction in which thermodynamic processes must be carried out and the impossibility of their occurrence in the opposite direction. It also establishes the impossibility of completely converting all the energy of one type into another without losses.

Explanation:

The first law of thermodynamics can be expressed as "energy is neither created nor destroyed, only transformed." This law defines heat as the necessary energy that the system must exchange to compensate for differences between work and internal energy.

In this way, the second law of thermodynamics imposes restrictions for energy transfers that could be carried out taking into account only the first principle. This law supports all its content and accepts the existence of entropy, so that, for an isolated system (there is no exchange of matter or energy with its surroundings), the variation of entropy must always be greater than zero.