Answers:
G. -; H. -; I. +
Step-by-step explanation:
ΔE = q + w
Anything going into the system is positive (+), and anything leaving the system is negative (-).
G. Cooling with expansion
q: Heat is leaving; q is -
w: The system is doing work on the surroundings. Energy is leaving the system. w is -.
ΔE is -.
H. Heating a little, expanding a lot
q: Heat is entering; q is +.
w: The system is doing work on the surroundings. Energy is leaving the system. w is -.
However, the expansion work is the major factor.
ΔE ≈ w. ΔE is -.
I. Endothermic, no expansion
q: Heat is entering; q is +.
w: No expansion. w = 0.
ΔE = q. ΔE is +.
