Gas solubility law identification:\n“The equilibrium mole fraction (or concentration) of a gas dissolved in a liquid is directly proportional to the partial pressure of that gas above the liquid.” This statement is ________ law.

Introduction / Context:
Quantifying how gases dissolve in liquids is essential for absorption columns, carbonation of beverages, aeration in bioreactors, and environmental modeling. The classic relationship between dissolved gas concentration and its partial pressure in the contacting gas is Henry’s law, valid at sufficiently low solubility and moderate pressures for many systems.

Given Data / Assumptions:

• Low to moderate gas solubility; dilute solution in the liquid phase.
• Constant temperature; Henry’s constant depends strongly on temperature.
• No chemical reaction between gas and solvent (otherwise, modified forms apply).

Concept / Approach:
Henry’s law: x_gas,liq = H_p^−1 * p_gas (pressure-based form) or C = H_c * p depending on convention. It states linear proportionality between dissolved concentration (or mole fraction) and gas partial pressure at a given temperature. Raoult’s law covers vapor–liquid equilibrium of volatile solvents (liquid-phase activity proportional to mole fraction). Amagat’s law applies to gas mixture volumes, not dissolution.

Step-by-Step Solution:

Verification / Alternative check:
Plotting dissolved oxygen vs oxygen partial pressure at fixed temperature produces a straight line through the origin under Henry’s regime.

Why Other Options Are Wrong:

• Raoult’s concerns volatile solvents, not a sparingly soluble gas in a liquid.
• Amagat’s concerns gas volumes, not solubility.
• “None of these” is incorrect because Henry’s law fits exactly.

Common Pitfalls:
Confusing Henry’s with Raoult’s; mixing units and definitions of Henry’s constant (several conventions exist).

Final Answer:
Henry’s law.