Question

A refrigerator removes 55.0 kcal of heat from the freezer and releases 73.5 kcal through the condenser on the back.How much work was done by the compressor

Answer 1

Here refrigerator removes 55 kcal heat from freezer

Refrigerator releases 73.5 kcal heat to surrounding

So here we can use energy conservation principle by II Law of thermodynamics

the law says that

$Q_1 = Q_2 + W$

here we know that

$Q_1$ = heat released to the surrounding

$Q_2$ = heat absorbed from freezer

W = work done by the compressor

now using above equation we can write

$73.5 = 55 + W$

$W = 73.5 - 55$

$W = 18.5 kcal$

So here compressor has to do 18.5 k cal work on it