Answer:
SO3
It has the highest molar mass value and thus would be the least soluble
Explanation:
In this question, we want to know which of the gases is the least soluble in water.
The easiest way to do this is to calculate the molar masses of these gases. The gas with the highest molar mass is the heaviest and thus will be the least soluble in water
For CO2 - molar mass is 44 g/mol
For SO3- molar mass is 80 g/mol
For N2- molar mass is 28g/mol
For NH3-molar mass is 17g/mol
For HCl- molar mass is 36.5 g/mol
From the molar masses, we can see that the molar mass of the ammonia gas is the lightest and thus, it is the most soluble.
The mass of the sulphur vi oxide is the highest and thus it is the heaviest and the least soluble in water