Question

Which of the following gases is most soluble in water?

• A. Oxygen
• B. Nitrogen
• C. Carbon dioxide
• D. Hydrogen

Hint:

Carbon dioxide's solubility is higher because it forms carbonic acid when dissolved in water, unlike other gases that only dissolve physically.

Answer 1

The Correct Option is C

Among the given gases, carbon dioxide is the most soluble in water. This is due to its ability to react with water to form carbonic acid: \[ \mathrm{CO_2 + H_2O \rightarrow H_2CO_3} \] This reaction increases its solubility significantly compared to other gases like oxygen, nitrogen, and hydrogen, which are relatively non-reactive and only physically dissolve in water.