Question

which of the following gases would you expect to behave most ideally under the same conditions of temperature and pressure? carbon dioxide (co₂) ammonia (nh₃) helium (he) water vapor (h₂o) consider two gases, methane (ch₄) and sulfur dioxide (so₂), at the same temperature and pressure. which gas is likely to exhibit more ideal behavior? both gases will exhibit the same degree of ideal behavior under these conditions. it is impossible to predict without knowing the exact temperature and pressure. methane (ch₄), because it has weaker intermolecular forces and smaller molecular size. sulfur dioxide (so₂), because it has stronger intermolecular forces and larger molecular size.

Explanation:

1. Ideal gas behavior is best exhibited by gases with weak intermolecular forces and small molecular size. Helium is a noble - gas with very weak intermolecular forces and a small atomic size compared to carbon dioxide, ammonia, and water vapor which have stronger intermolecular forces like dipole - dipole or hydrogen bonding.
2. Among methane and sulfur dioxide, methane has weaker intermolecular forces (London dispersion forces) and a smaller molecular size compared to sulfur dioxide which has stronger dipole - dipole forces and a larger molecular mass/size. So methane is more likely to exhibit ideal gas behavior.

Answer:

1. Helium (He)
2. Methane ($CH_4$), because it has weaker intermolecular forces and smaller molecular size.