Under which of the following conditions is a gas least likely to be ideal?

• A. high pressure, low temperature
• B. low pressure, high temperature
• C. high pressure, high temperature
• D. low pressure, low temperature

Answer: (A)

Verified step by step guidance

1. Understand the concept of an ideal gas: An ideal gas is a theoretical gas composed of many randomly moving point particles that interact only through elastic collisions. The behavior of an ideal gas is described by the ideal gas law: <math xmlns='http://www.w3.org/1998/Math/MathML'><mi>P</mi><mi>V</mi>=<mi>n</mi><mi>R</mi><mi>T</mi></math>, where <mi>P</mi> is pressure, <mi>V</mi> is volume, <mi>n</mi> is the number of moles, <mi>R</mi> is the ideal gas constant, and <mi>T</mi> is temperature.
2. Recognize the conditions under which real gases deviate from ideal behavior: Real gases deviate from ideal behavior at high pressures and low temperatures. This is because the assumptions of the ideal gas law (no intermolecular forces and negligible volume of gas particles) become less valid.
3. Analyze the effect of high pressure: At high pressure, gas particles are forced closer together, increasing the effect of intermolecular forces and the volume occupied by the gas particles themselves, leading to deviations from ideal behavior.
4. Analyze the effect of low temperature: At low temperatures, gas particles have less kinetic energy and move more slowly, which increases the effect of intermolecular attractions, causing deviations from ideal behavior.
5. Evaluate the given conditions: Compare the conditions provided (high pressure, low temperature; low pressure, high temperature; high pressure, high temperature; low pressure, low temperature) to determine which scenario is most likely to cause a gas to deviate from ideal behavior. The combination of high pressure and low temperature is most likely to result in non-ideal behavior.