Question

2.50 mol of a diatomic ideal gas expands adiabatically and quasi-statically. The initial temperature of the gas is 325 K. The work done by the gas during expansion is 7.50 kJ.

(a) What is the final temperature of the gas?

K

(b) Compare your result to the result you would get if the gas were monatomic. (Calculate the final temperature if the gas were monatomic.)
K

Answer 1

where dU is the change in the internal energy of the system and ?W is work done by the system. Any work (?W) done must be done at the expense of internal energy U, since no heat ?Q is being supplied from the surroundings. Pressure-volume work ?W done by the system is defined as

It is desired to know how the values of dP and dV relate to each other as the adiabatic process proceeds. For an ideal gas the internal energy is given by

a)

7.5*1000=1.4*2.5*8.314(T-325)

T=582.74k

b)

7.5*1000=1.66*2.5*8.314*(T-325)

T=542.37K