Difinations of chemical engg thermodynamics
Answers
Answer:
Chemical thermodynamics is the study of the interrelation of heat and work with chemical reactions or with physical changes of state within the confines of the laws of thermodynamics. Chemical thermodynamics involves not only laboratory measurements of various thermodynamic properties, but also the application of mathematical methods to the study of chemical questions and the spontaneity of processes.
The structure of chemical thermodynamics is based on the first two laws of thermodynamics. Starting from the first and second laws of thermodynamics, four equations called the "fundamental equations of Gibbs" can be derived. From these four, a multitude of equations, relating the thermodynamic properties of the thermodynamic system can be derived using relatively simple mathematics. This outlines the mathematical framework of chemical thermodynamics
Explanation:
To understand thermodynamics, it's helpful to first define something called a system. A system is a series of components that are connected together. In a nutshell, it's the part of the world we're focusing on. We can look at what moves in and out of a particular system. For example, if we have coffee in a thermos flask, we can either call the coffee itself the system, or the whole thermos flask (including the walls of the container).
There are several types of systems in chemical thermodynamics: isolated systems, closed systems, and open systems.
An isolated system is one that has rigid walls and doesn't allow the transfer of energy or mass. The walls are perfectly insulating. A closed system has walls that let energy pass in and out of the system, but that don't allow mass to enter or escape. And an open system allows both energy and matter to enter and leave.
Laws of Thermodynamics
There are several important laws of thermodynamics, which form the cornerstone of the field. The first law of thermodynamics says that the change in the internal energy of a closed system equals the heat added to the system, minus the work done by the system on the surroundings. This also means that in an isolated system, the energy changes inside the system must be zero.
The second law of thermodynamics says that the entropy in the universe must always increase. Entropy is the amount of disorder in the universe, measured in joules per kelvin. So this means the universe always becomes more disorderly. Let's say that you decide to tidy your home: you put away the books in alphabetical order, wash the dishes and store them in neat piles. You might think you've just made the universe more orderly, and in some ways you have, but in the universe as a whole this is impossible. By using your muscles to tidy things up, you've produced heat energy in your arms, and that heat energy has overall made the universe less orderly.
Gasses are more disorderly than liquids and solids, and so have a greater entropy
Another consequence of the second law of thermodynamics is that heat can only travel spontaneously from hot places to cold places. This means that a refrigerator can't work on its own. The only way to make a refrigerator work is by doing work - by using energy from the electricity supply in the wall. Turn off the electricity, and heat will move from hot places (the room) to cold places (the refrigerator) just like normal.