Question

During an adiabatic process, the temperature of 3.92 moles of a monatomic ideal gas drops from 485 ^oC to 205 ^oC. For this gas, find (a) the work done by the system and (b) the net heat absorbed by the system.

Answer 1

For adiabatic process there is no heat transfer betweeen the system and the surroundings. Hence the net heat absorbed or released by the system is zero.

(a) Since it is a monoatomic gas, the degrees of freedom f is 3, Therefore we can calculate,

The total change in internal energy of the system is,

Now since the transfer of heat is zero, therefore we can write, the work done as.

Therefore the work done by the system is 13681.58 J which leads to the cooling of the system, and decrease in internal energy.

(b) As said earlier, in an adiabatic process there is no heat transfer between the system and the surroundings. Therefore the net heat absorbed by the system is zero.