Question

which of the following statements is true for real gases? choose all that apply. o as molecules increase in size, deviations from ideal behavior become more apparent at relatively high pressures. o as attractive forces between molecules increase, deviations from ideal behavior become more apparent at relatively high temperatures. o the volume occupied by the molecules can cause an increase in pressure compared to the ideal gas. o attractive forces between molecules cause an increase in pressure compared to the ideal gas.

Explanation:

• Molecular size: As molecules increase in size, they occupy more space. In an ideal gas, molecules are assumed to have no volume. So, at relatively high pressures (where the volume of the gas is reduced), the non - zero volume of real gas molecules becomes more significant, causing deviations from ideal behavior.
• Attractive forces: In an ideal gas, there are no intermolecular forces. At relatively low temperatures, the kinetic energy of the molecules is reduced. The attractive forces between real gas molecules can then have a more pronounced effect. These forces can cause the molecules to be pulled closer together, reducing the pressure compared to what would be expected for an ideal gas (since pressure in an ideal gas is due to elastic collisions of non - interacting molecules).
• Volume occupied by molecules: At high pressures, the volume of the gas is compressed. The volume occupied by the real gas molecules themselves (which is neglected in the ideal gas model) becomes a larger fraction of the total volume of the gas sample. This causes the real gas to deviate from the ideal gas law (\(PV = nRT\), which assumes \(V\) is the volume available for molecular motion, not considering molecular volume).

Answer:

As molecules increase in size, deviations from ideal behavior become more apparent at relatively high pressures. As attractive forces between molecules increase, deviations from ideal behavior become more apparent at relatively high temperatures. The volume occupied by the molecules can cause an increase in pressure compared to the ideal gas. Attractive forces between molecules cause an increase in pressure compared to the ideal gas.