(a) List two experimental conditions under which gases deviate from ideal behavior. (b) List two reasons why the gases deviate from ideal behavior.

To find two experimental conditions under which gases deviate from ideal behavior, let's discuss the ideal gas law and conditions that cause deviations from this law. The ideal gas law is given by the equation PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature. Gases deviate from ideal behavior when they are subjected to conditions that cause significant interactions between gas particles or when the gas particles themselves occupy a substantial fraction of the gas volume. 1. High Pressure: Under high pressure conditions, the gas particles are compressed and are closer to each other. The intermolecular forces between the particles become significant, leading to deviations from ideal behavior. 2. Low Temperature: At low temperatures, the kinetic energy of the gas particles decreases and, as a result, gas particles move slower. The intermolecular forces between particles become more important in determining their behavior as their relative motion slows down.

Now, let's discuss two specific reasons why gases deviate from ideal behavior under these experimental conditions: 1. Intermolecular forces: Ideal gas law assumes that there are no forces between the gas particles and any interaction between them is elastic. However, in reality, gas particles do experience various intermolecular forces (such as van der Waals forces or hydrogen bonding). These forces become particularly significant at high pressures and low temperatures, causing gases to behave non-ideally. 2. The volume of gas particles: According to the ideal gas law, gas particles are considered to have negligible volume. In reality, gas particles occupy a finite volume, and this becomes important under high-pressure conditions. When the pressure is high, the volume occupied by the gas particles themselves becomes a significant fraction of the overall volume of the gas, leading to deviations from the ideal gas law.