Answer
a. $\Delta H = \Delta E$
b. $\Delta H < \Delta E$
c. $\Delta H > \Delta E$
Work Step by Step
Note that $\Delta H = \Delta E +P\Delta V$.
a. The number of liters remains the same. Therefore $\Delta V$ is 0 and $\Delta H = \Delta E$.
b. The number of liters decreases from 4 to 2. Therefore $\Delta V<0$ and $\Delta H < \Delta E$
c. The number of liters increases from 9 to 10. Therefore $\Delta V>0$ and $\Delta H > \Delta E$