Question about the rules of thermodynamics

Thread starter samy4408
Start date Apr 6, 2022
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Enthalpy Gibbs free energy Reaction Rules Thermodaynamics Thermodynamics

In summary, the three laws of thermodynamics are: the conservation of energy, the increase of entropy over time, and the relationship between temperature and entropy. These laws can be observed in everyday life, as seen in electrical appliances, the tendency for things to become more disordered, and the impossibility of reaching absolute zero temperature. There are three types of systems in thermodynamics: open, closed, and isolated, which differ in their ability to exchange matter and energy with their surroundings. The laws of thermodynamics are fundamental and cannot be broken, and they play a crucial role in understanding and improving energy efficiency by setting limits on energy conversion processes.

Apr 6, 2022

samy4408

Hello , we learned in thermodynamics that to calculate ΔHr °(of the reaction ) using ΔHf °(standard heat of formation ), we have to respect that
ΔHf °=ΔHr ° of a reaction forming 1 mol of compound from pure elements in their most stable form at standard state .
the problem is when we want to calculate ΔGr ° using ΔGf ° is it necessary to respect the rule raised before ?
thanks .

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Apr 6, 2022

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Yes.

FAQ: Question about the rules of thermodynamics

1. What are the three laws of thermodynamics?

The three laws of thermodynamics are:
1. The first law, also known as the law of conservation of energy, states that energy cannot be created or destroyed, only transferred or converted from one form to another.
2. The second law states that the total entropy of a closed system will always increase over time, meaning that energy tends to disperse and become less usable.
3. The third law states that it is impossible to reach absolute zero temperature (0 Kelvin) through any finite number of steps.

2. How do the laws of thermodynamics apply to everyday life?

The laws of thermodynamics are fundamental principles that apply to all energy and matter in the universe, including in our daily lives. They are used to explain and understand various phenomena, such as the transfer of heat, the functioning of engines, and the behavior of gases. They also have practical applications in fields such as chemistry, physics, and engineering.

3. Can the laws of thermodynamics be broken?

No, the laws of thermodynamics are considered to be universal and absolute. They have been extensively tested and have never been found to be violated. However, there may be situations where it appears that the laws are being broken, but this is usually due to incomplete or incorrect understanding of the system in question.

4. How do the laws of thermodynamics relate to entropy?

The second law of thermodynamics states that the total entropy of a closed system will always increase over time. Entropy is a measure of disorder or randomness within a system. As energy is transferred or converted, it tends to become more dispersed and less organized, leading to an increase in entropy. This is why the second law is often referred to as the law of increasing entropy.

5. Are there any exceptions to the laws of thermodynamics?

There are no known exceptions to the laws of thermodynamics. However, there are certain systems that may appear to defy the laws, such as living organisms that are able to maintain a high level of organization and decrease their entropy. However, these systems still follow the laws of thermodynamics, as they are open systems that exchange energy and matter with their surroundings. In addition, the laws may not fully apply at the quantum level, but this is an area of ongoing research and debate among scientists.