Solubility of Gas in Liquids — Prelims Strategy

Prelims Strategy

To excel in NEET questions on 'Solubility of Gas in Liquids', a systematic approach is essential. For numerical problems involving Henry's Law ($P = K_H x$), always start by ensuring all units are consistent.

If partial pressure is in atmospheres, convert $K_H$ to atmospheres as well. Pay close attention to the powers of ten in scientific notation. Practice rearranging the formula to solve for $P$, $K_H$, or $x$.

For conceptual questions, recall the fundamental principles: gas solubility generally decreases with increasing temperature (exothermic process, Le Chatelier's Principle) and increases with increasing partial pressure.

Remember that a higher $K_H$ value means lower solubility. For questions on the nature of gas and solvent, apply the 'like dissolves like' rule and consider chemical reactivity; gases that react with the solvent (e.

g., $ext{NH}_3$ in water) exhibit exceptionally high solubility, and Henry's Law may not strictly apply. Be wary of trap options that confuse the effects of temperature on gas solubility versus solid solubility, or misinterpret the meaning of $K_H$.

Always read the question carefully to identify what is being asked (e.g., highest solubility vs. highest $K_H$).