MHTCET 13 Apr 2026 Shift 1 Paper

Concept:Gases that dissolve in a liquid without undergoing a chemical reaction obey Henry’s law.Gases that react with the solvent show deviation from Henry’s law.Explanation:Henry’s law relates the solubility of a gas to its partial pressure.It holds well for gases like $\mathrm{N}_{2}$, $\mathrm{O}_{2}$, and $\mathrm{CH}_{4}$, which dissolve physically in water without reacting.However, $\mathrm{NH}_{3}$ and $\mathrm{CO}_{2}$ react chemically with water.Ammonia forms ammonium hydroxide:$$\mathrm{NH}_{3} + \mathrm{H}_{2}\mathrm{O} \rightleftharpoons \mathrm{NH}_{4}^{+} + \mathrm{OH}^{-}$$Carbon dioxide forms carbonic acid:$$\mathrm{CO}_{2} + \mathrm{H}_{2}\mathrm{O} \rightleftharpoons \mathrm{H}_{2}\mathrm{CO}_{3}$$Due to these reactions, their solubility depends on chemical equilibrium and not only on pressure.Therefore, $\mathrm{NH}_{3}$ and $\mathrm{CO}_{2}$ do not obey Henry’s law properly.Answer:Option A: $\mathrm{NH}_{3}$ and $\mathrm{CO}_{2}$