q and w = 0

[Samantha Chung 4I]

Is there a specific set of conditions under which we can assume q and w equals to zero? Or does it depend on the problem?

[Meachelle_Lum_1I]

q=0 if the problem is adiabatic.
w=0 if there is no volume change.
q=-w if deltaU=0, which occurs when the system is in isothermal conditions. This is because isothermal occurs at a constant temperature, and for ideal gases, U=3/2nRT. For solids and liquids, q=-w because U=q+w.
q and w will both be 0 for isolated conditions, in which no heat or work can be transferred.

[Rimsha Hussaini 1A]

If no heat was exchanged in the system, q = 0 and deltaU = w.
If no work was being done in the system, w = 0 and deltaU = q.
For an ideal gas in an isothermal system, deltaU = 0 = q + w. In this situation, q = nRTln(V2/V1).

[Charles Hood Disc 1C]

If an ideal gas is "isothermal" then you can assume ΔU = 0.