22. The First Law of Thermodynamics

Two moles of an ideal gas are heated at constant pressure from $T = 27$°C to $T = 107$°C. Draw a $pV$-diagram for this process.

Two moles of an ideal gas are heated at constant pressure from $T=27$°C to $T=107$°C. Calculate the work done by the gas.

An ideal gas is taken from $a$ to $b$ on the $pV$-diagram shown in Fig. E$19.15$. During this process, $700$ J of heat is added and the pressure doubles. How does the internal energy of the gas at $a$ compare to the internal energy at $b$? Be specific and explain.

Figure E$19.8$ shows a $pV$-diagram for an ideal gas in which its absolute temperature at $b$ is one-fourth of its absolute temperature at $a$. Did heat enter or leave the gas from $a$ to $b$? How do you know?

A PV diagram shows a straight horizontal line from point A at $P=2 atm$, $V=1 L$ to point B at $P=2 atm$, $V=4 L$. Which thermodynamic process does this diagram represent?