The document describes a gas confined in a container that is heated, causing it to expand against a constant external pressure. It provides the initial conditions and asks to calculate: (1) The new volume after expansion is 0.4 L (2) The work done during expansion is 0.1974 l-atm (3) The change in internal energy is 0 since temperature is constant (4) The change in enthalpy is 2 J, equal to the heat supplied