Thermodynamics and gases?

Question

A rigid container contains 1.0 mol of an ideal gas that slowly receives 2.0 × 10^4 J of hear.

Is the work done by the gas
(a) Positive
(b) Zero
(c) Negative

Why?

Is a net amount of hear added to or removed form the system and how much is involved?

Answer 1

The work done is zero since the container is rigid, meaning there is no volume change and thus no displacement (e.g., of a piston).
The question is oddly stated ("...slowly receives...heat") given that there is no volume change. The system could receive the heat rapidly and the answer would be the same. Slowness of heat transfer typically characterizes isothermal expansion against a slightly larger external force, which os not the case here.
The question itself states the amount of heat added to the system.