Question

In an adiabatic expansion of an ideal gas

• A. q=0
• B. dT=0
• C. $\Delta U$=0
• D. W = 0

Answer 1

Answer: (A)

q = 0

Answer 2

For an adiabatic process, by definition, there is no heat exchange with the surroundings. Thus,

$$q = 0.$$

Using the first law of thermodynamics:

$$\Delta U = q + W,$$

for an adiabatic process it becomes:

$$\Delta U = W.$$

However, this does not imply that $\Delta U = 0$ or $W = 0$ in general, and there is a change in temperature unless stated otherwise.