Question

How is the presence of $S{{O}_{2}}$ detected?

Answer 1

Hint: By its smell and colour one can recognise its presence. $S{{O}_{2}}$has a very pigment smell, it is colourless. When $S{{O}_{2}}$ion is passed in an acidic potassium permanganate solution it decolonises the solution.

Complete step-by-step answer:
By following the reaction, we can recognise the presence of $S{{O}_{2}}$.
$5S{{O}_{2}}+2Mn{{O}_{4}}+2{{H}_{2}}O\,\to \,5S{{O}_{4}}+4H+S{{O}_{2}}$
It also turns orange colour of acidic ${{K}_{2}}C{{r}_{2}}{{O}_{7}}$ into green colour as it reduces
$S{{O}_{2}}$ is a gas with colourless and pungent smell it can be detected with the help of $KMN{{O}_{4}}$ solution test in which when we pass $S{{O}_{2}}$ through an acidified $KMN{{O}_{4}}$ solution it does the decolonization of the solution as it helps in the reduction of $Mn{{O}^{4-}}$ ions to $M{{n}^{2+}}$ ions.
Sulphur dioxide is quite irritating gas and gets easily dissolved to the water and main constituent of the acid rain.
Sulphur dioxide is a very toxic gas and exists in very small concentrations. Sulphur dioxide has an intermediate stage for the production of sulphuric acid. Sulphur dioxide is also used in the preservation of many fruits and food. Most of the time we can get this sulphur dioxide from the air. Although there are some mineral ores too which helps in the production of the sulphur dioxide gas.

Note: By its colour and smell and its reducing nature we can detect it. Further this gas reacts easily with any other element to form the various kinds of hazardous compounds which can be sulphurous acid, sulphates and also sulphuric acid sometimes. The presence of the sulphur dioxide gas most of the time results in the discolouration of the compound it is getting reacted to.