Question

For a gas, deviation from ideal behaviour is maximum at:

• A. \(0^{\circ}C\) & 1.0 atm
• B. \(-25^{\circ}C\) & 5.0 atm
• C. \(-25^{\circ}C\) & 2.0 atm
• D. \(100^{\circ}C\) & 1.0 atm

Hint:

Real gases deviate from ideal behavior under conditions of high pressure and low temperature due to the increased significance of intermolecular forces and the non-negligible volume of gas molecules.

Answer 1

The Correct Option is B

Deviation from ideal behavior is maximum when the intermolecular forces become significant. This happens at:

• Low Temperatures: At low temperatures, the kinetic energy of the gas molecules is low, and the intermolecular forces become more dominant.
• High Pressures: At high pressures, the molecules are forced closer together, increasing the effect of intermolecular forces and reducing the free volume available for the molecules.

Comparing the options:

• (1) \(0^{\circ}C\) & 1.0 atm: Relatively moderate conditions.
• (2) \(-25^{\circ}C\) & 5.0 atm: Low temperature and high pressure, favoring maximum deviation.
• (3) \(-25^{\circ}C\) & 2.0 atm: Low temperature but lower pressure than option (2).
• (4) \(100^{\circ}C\) & 1.0 atm: High temperature and low pressure, favoring ideal behavior.

Therefore, the maximum deviation from ideal behavior occurs at \(-25^{\circ}C\) and 5.0 atm.

Final Answer:
\(-25^{\circ}C\) & 5.0 atm.