Question

Name a gas that cannot be collected over water

Answer 1

A gas that cannot be collected over water:-

• Gas can be collected over water surfaces if it doesn't get dissolved in water and cannot be collected over water surfaces if it gets dissolved in water.
• Gases that do not dissolve in water are Carbon Dioxide(${\mathrm{CO}}_2$), Carbon Monoxide($\mathrm{CO}$), etc.
• $\underset{\mathrm{Carbon}\mathrm{Dioxide}}{{\mathrm{CO}}_2}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}}\to \underset{\mathrm{Carbonic}\mathrm{Acid}}{{\mathrm{H}}_2{\mathrm{CO}}_3}$
• Hence, it can't be collected over water.

Therefore, Carbon Dioxide(${\mathrm{CO}}_2$) is a gas that cannot be collected over water surfaces.