Answer:
HBr - Attractive forces.
Step-by-step explanation:
Generally, there are limitations to the ideal gas equation are summarized as;
The ideal-gas law assumes that there are no forces of attraction between the individual gaseous molecules. Whenever this isn’t so, real molecules will not obey the ideal-gas law. This would be expected to occur at very high pressures and at very low temperatures where molecules are so close to one another that they necessarily interact.
The ideal-gas law also assumes that the gas particles have no volume. At high pressures their volume may become appreciable relative to the volume of the container.
You would expect H2 to behave more like an ideal gas because it has a smaller molar mass and would occupy a smaller volume. This means that the intermolecular attractive forces are smaller than that of HBr and therefore, it is more like an ideal gas.
Hbr has a stronger intermolecular force and hence is expected to deviate more from the ideal gas equation.