Concept explainers
A pot is half-filled with water, and a lid is placed on it, forming a tight seal so that no water vapor can escape. The pot is heated on a stove, forming water vapor inside the pot. The heat is then turned off and the water vapor condenses back to liquid. Is this cycle reversible or irreversible? Why?
Whether the process of forming water vapor inside the pot and condense back to liquid is a reversible cycle or irreversible cycle.
Explanation of Solution
A reversible is the one which can be reversed in such a way that all changes occurring in the process in forward direction can be exactly repeated in the opposite order. Any process which does not meet this requirement is called irreversible process.
When the pot is heated on stove, formation of water vapor occurs inside the pot. When the heat is turned off, the water vapor inside the pot starts cooling and transform into liquid form. This cooling process occurs at very slow rate. This is because the cycle can be reversed at any point in forward direction or backward direction by increasing or decreasing the heat input to the pot.
Conclusion:
The vapor formation of water inside the tight sealed pot and condensation of this water vapor is reversible process as initial position can be restored to by reducing or increasing the supply of heat.
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