At a certain temperature, the degrees of freedom per molecule for gas is 8 . The gas performs 150 J of work when it expands under constant pressure. The amount of heat absorbed by the gas will be ____

Question

At a certain temperature, the degrees of freedom per molecule for gas is 8 . The gas performs 150 J of work when it expands under constant pressure. The amount of heat absorbed by the gas will be _____ J .

TestHub · Accepted Answer

For constant pressure process,
Work done is given by $W = n R Δ T = 150 J$ , here, $R$ is gas constant.
Now, for above process, $f = 8$ .
So, specific heat at constant pressure is $C_{P} = (1 + \frac{f}{2}) R$ .
Amount of heat adsorbed by the gas is
$Q = n C_{P} R Δ T = (\frac{f}{2} + 1) n R Δ T = (\frac{8}{2} + 1) 150 = 750 J$

Physics - Heat & Thermo Question with Solution | TestHub

Doubts & Discussion