The temperature of 7.10 mol of an ideal monatomic gas is raised 15.0 K in an adiabatic process. What are (a) the work W done by the gas, (b) the energy transferred as heat Q, (c) the change ÄEint in internal energy of the gas, and (d) the change ÄK in the average kinetic energy per atom?

Answer 1

Start with part c). In case of an ideal gas, the internal energy only depends on temperature. In case of a monoatomic gas we have:

E = 3/2 N k T

here k is Boltzmann's constant and N is given as

N = 7.1 mol = 4.276*10^24

So, we have:

E = 88.55 J/K T

If the temperature is raised by 15 , then the increase in E is thus 1328 J.

The change in internal eenrgy is also equal to the heat abosorbed minus the work done by the gas. An adiabatic change means, by definition, that the absorbed heat is zero. So, the work done by the gas is minus 1328 J.