During an isothermal expansion, a confined ideal gas does –150 J of work against its surrounding. This implies that :
Answer & explanation
Correct answer: option 1
By first law of thermodynamics, ΔU = Q + W
For isothermal process, ΔU = 0
Thus, Q = – W ; W = – 150 Q = + 150
Thus, 150 J of heat is added to the gas.