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JJBladester
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Homework Statement
Show that processes involving rapid chemical reactions are irreversible by considering the combustion of a natural gas (e.g. methane) and air mixture in a rigid container.
Homework Equations
[tex]Q_{in}+W_{e,in}-W_{b}=\Delta U+\Delta KE+ \Delta PE[/tex]
The Attempt at a Solution
I know that an irreversible process is one that, when reversed, have some effect on the surroundings. Common irreversibilities are friction, unrestrained expansion, mixing of two fluids, heat transfer across a finite temperature difference, electrical resistance, inelastic deformation of solids, and chemical reactions.
This problem deals with the mixing of two fluids. Does it also deal with unrestrained expansion?
The problem says that the chemical reaction is "rapid" which immediately sets off the idea of irreversibility, and it also says the combustion happens in a "rigid" container which means the total volume inside the container never changes.
I know that combustion causes temperature and pressure to increase.
The heat produced by the gas during combustion equals the amount of work it would require to put the surroundings back to their original state, right?
How do I put all of these thoughts into a statement proving the irreversibility of combustion in a rigid chamber?