22. The First Law of Thermodynamics

An ideal gas is taken through the four processes shown below. The changes in internal energy for three of these processes are as follows: ΔE_AB = +82 J; ΔE_BC = +15 J; ΔE_DA =–56 J. Find the change in internal energy for the process from C to D.

0.25 mol of a gas are compressed at a constant pressure of 250 kPa from 6000 cm³ to 2000 cm³, then expanded at a constant temperature back to 6000 cm³. What is the net work done on the gas?

A gas following the pV trajectory of FIGURE EX21.11 does 60 J of work per cycle. What is V_max?

A heat engine using a diatomic gas follows the cycle shown in FIGURE P21.55. Its temperature at point 1 is 20℃. Determine W_s, Q, and ∆E_th for each of the three processes in this cycle. Display your results in a table.

A heat engine uses a diatomic gas that follows the pV cycle in FIGURE P21.59. Determine the pressure, volume, and temperature at point 2.