Question

Which of the following gas is insoluble in water?
a.) SO$_2$
b.) H$_2$
c.) NH$_3$
d.) CO$_2$

Answer 1

Hint: The solubility of gases in water depends upon the intermolecular interaction and polarity of the gas. H$_2$ is a non-polar gas, whereas the others mentioned are polar in nature.

Complete step by step answer:
First, we will know that the solubility of gases in water depends upon intermolecular interaction present between the bonds and the bonds must be polar enough to show the solubility
Now, if we talk about the mentioned options, first is SO$_2$, it is a polar molecule and the strong intermolecular interactions are present between the sulphur, and oxygen, making it soluble in water.
Talking about the second option, i.e. H$_2$ is a non-polar molecule, the interaction between H-H bond is weak as compared to other gases, so it is insoluble in water.
Now, if we see the third option, NH$_3$ is a polar gas, the bond between nitrogen, and hydrogen is too polar, making it highly soluble in water.
The fourth option is CO$_2$, if we talk about it, the bond between carbon and oxygen is less polar, but it is polar enough to be soluble in water.
So, gas is insoluble in water. The correct option is B.

Note: Don’t get confused between the polar, and nonpolar molecules. The intermolecular interaction between the molecules formed from two different elements is usually higher than the diatomic molecules.