Which gas would you expect to deviate more from ideality, h2 or hbr? explain your answer. which factor is the major cause for deviation from ideal behavior, the volume of the cl2 molecules or the attractive forces between them?

Deviation of ideal gas is mainly due to interaction between the particles itself, the more they interact with each other, the more it deviates.

HBr deviate more from ideality because of the high electronegativity of bromine. an ideal gas has molecules that preform elastic collision, because bromine is solo electro negative, it may begin to attract slight positive charge of hydrogen atom on other molecules. H2 does not have dipole moment so would act like an ideal gas.

HBr - Attractive forces.

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.