Calculate 🔺E if 100kJ of heat energy is absorbed by the system and 30kJ of work is done on the surroundings.
As given that work is done on the surroundings and heat is absorbed by the system.
q = 100kJ
w = −30kJ
Now, from first law of thermodynamics,
Change in internal energy-
ΔU = q + w
⇒ ΔU = 100 + (−30) = 70kJ
Hence, ΔE is 70kJ