MHTCET 18 Apr 2026 Shift 2 Paper

Concept:Solubility of a gas in water depends on its polarity and its ability to react with or form hydrogen bonds with water molecules.Explanation:Water is a polar solvent, so polar gases and gases that can react with water dissolve more readily.$\mathrm{NH}_3$ is highly soluble because it forms hydrogen bonds with water and also reacts slightly:$$\mathrm{NH}_3 + \mathrm{H}_2\mathrm{O} \rightleftharpoons \mathrm{NH}_4^+ + \mathrm{OH}^-$$HCl is extremely soluble because it ionises completely in water:$$\mathrm{HCl} \rightarrow \mathrm{H}^+ + \mathrm{Cl}^-$$$\mathrm{CO}_2$ is moderately soluble because it reacts with water to form carbonic acid:$$\mathrm{CO}_2 + \mathrm{H}_2\mathrm{O} \rightleftharpoons \mathrm{H}_2\mathrm{CO}_3$$$\mathrm{N}_2$ is a non-polar gas that neither reacts with water nor forms hydrogen bonds with it.Hence, its attraction to water molecules is very weak, making it the least soluble.Therefore, nitrogen gas has the lowest solubility among the given gases.Answer:Option D: $\mathrm{N}_2$