The correct answer is Option (3) → (A), (B), (C) and (D)
(A) Nature of the gas
- Effect: The chemical nature of the gas is critical. Gases that can react with the solvent (like $HCl$ or $NH_3$ in water) or form strong intermolecular forces (like polar gases in polar solvents, or non-polar gases in non-polar solvents, following the "like dissolves like" rule) are generally more soluble.
- Conclusion: Yes, solubility depends on the nature of the gas.
(B) Pressure at constant temperature
- Effect: For gases, solubility is directly proportional to the partial pressure of the gas above the liquid. This relationship is quantified by Henry's Law. Increasing the pressure forces more gas molecules into the liquid phase, increasing solubility.
- Conclusion: Yes, solubility depends on pressure (at constant temperature).
(C) Temperature at constant pressure
- Effect: The dissolution of a gas in a liquid is almost always an exothermic process (releases heat). According to Le Chatelier's principle, increasing the temperature shifts the equilibrium in the direction that consumes heat, which is the reverse direction (gas coming out of solution). Therefore, increasing temperature decreases the solubility of most gases in liquids.
- Conclusion: Yes, solubility depends on temperature (at constant pressure).
(D) Nature of solvent
- Effect: The chemical nature of the solvent is also crucial. A gas will be more soluble in a solvent that has similar intermolecular forces (e.g., a non-polar gas like $O_2$ is more soluble in a non-polar solvent like hexane than in water). This is again governed by the "like dissolves like" principle.
- Conclusion: Yes, solubility depends on the nature of the solvent.
Final Selection
All four factors—the nature of the gas, the pressure, the temperature, and the nature of the solvent—significantly affect the solubility of a gaseous solute in a liquid solvent. |
