Question

Which gas cannot collect over Water?
    \[\begin{array}{l}
A.\, \, \, {O_2} \\
B.\, \, P{H_3} \\
C.\, \, {N_2} \\
D.\, S{O_2}
\end{array}\]

Answer 1

Hint: Gases do not exist in our atmosphere. They can be kept inside some containers for a period of time but after some time the gas tends to Bounce around the container to return back to the atmosphere.

Complete step by step solution:
> Consider a balloon filled with the helium gas, the atoms will keep making and equilibrium with the environment and proceeds out of the balloon constantly. One by one the atoms emerge out from the balloon to the atmosphere. So as in case of\[S{O_2} \], Sulphur dioxide is an insoluble gas which cannot be collected over Water as compared to soluble gases they dissolve easily into the water and it is tough to separate them from water. Sulphur Dioxide reacts with the water and produces sulfuric acid.
\[S{O_2} + {H_2} O \to {H_2} S{O_3} \]
> Sulphuric acid does not exist in the solution form but we can find out its molecule in the gas phase. Sulphuric acid acts as an intermediate species and helps in the acid rain formation from Sulphur dioxide.

The correct answer is D.

> Aqueous solution of Sulphur dioxide or sulfuric acid can be used as the reducing agents or reductants which are the compounds that lose some electrons in a Redox reaction. So, reducing agents gets oxidized while donating the electrons. Aqueous Sulphur Dioxide can also act as a disinfectant as the solution consists of bisulfite and sulfite salts. They accept oxygen atoms to oxidise the sulphuric acid.

Note: Insoluble substances like sulfuric acid cannot be collected over Water as that does not get dissolved in the water and for a gas to be soluble the solubility should be directly proportional to the pressure on the surface of the gas of solution.