For a real gas obeying the Van der Waals equation, if the 'a' parameter is very large and the 'b' parameter is very small, which of the following is true?
Correct: A
In the Van der Waals equation:
- The 'a' parameter accounts for intermolecular attractive forces. A very large 'a' indicates very strong attractive forces between gas molecules.
- The 'b' parameter accounts for the finite volume occupied by the gas molecules. A very small 'b' implies that the molecular volume is negligible.
When 'a' is very large, the attractive forces are very strong. These strong attractive forces pull molecules closer together, reducing the effective pressure exerted by the gas. This makes the gas more compressible than an ideal gas at moderate pressures. The presence of strong attractive forces also means significant deviation from ideal behavior (which assumes no attractive forces). While 'b' being small would lead to more ideal behavior concerning volume, the large 'a' (strong attractive forces) is the dominant factor for deviation. Therefore, the gas deviates significantly from ideal behavior due to strong attractive forces, and this facilitates compression.