A refrigerator moves heat from cold to warm.Why does this not violate the second law of thernodynamics?

Answer 1

Actually, it moves any heat from the foods to the cold - the evaporator which absorbs the heat. Just like the second law dictates it must.

Answer 2

A refrigerator is the best example to demonstrate the second law of thermo dynamics.

Clausius statement of second law of thermodynamics is:

It is impossible for a self acting mechanism UNAIDED by an external agency to transfer heat from a cold body to a hot body.

Explanation of the above statement is:

The natural process of heat is to flow from hot body to cold body. To transfer heat from a cold body to hot body an external work must be done. With out this external work heat cannot be transferred from a cold body to hot body.

When such a work is done on the cold body, a part of the work is utilized to remove some quantity of heat from the cold body and to give it to the hot body. The remaining part of the work is directly utilized to heat the hot body. We cannot make the second part of the work to be equal to zero.

This is implied in Clausius statement.

With out supplying work (Electrical Energy) the refrigerator cannot cool an object below the temperature of its surroundings.

Answer 3

A refrigerator uses energy to cool down a coolant, which is then circulated. The heat from the food is absorbed by the coolant, which is then cooled off again using energy. So, the refrigerator is using energy to create order out of disorder.