Why bleaching by sulphur dioxide is temporary while that done by chlorine is permanent?

The bleaching action of sulphur dioxide is temporary because it involves the process of reduction. Sulphur dioxide removes oxygen from the coloured substance and makes it colourless. Atmospheric oxygen slowly takes place of the removed oxygen and because of which the material regains its colour.

Does chlorine bleaches by oxidation or reduction?

Bleaching action of chlorine is permanent because it involves the oxidation process.

Why bleaching of chlorine is an oxidation reaction?

When chlorine reacts with water to form hydrochloric acid, which is unstable and quickly dissociates to form nascent oxygen. Nascent oxygen is a more powerful oxidising agent. Hence, the formation of nascent oxygen is responsible for the bleaching nature of chlorine in the presence of moisture.

How does bleaching action of chlorine differ from that of sulphur dioxide?

The key difference between bleaching action of SO2 and Cl2 is that bleaching action of SO2 proceeds through a reduction reaction and is a temporary bleaching process whereas bleaching action of Cl2 proceeds through an oxidation reaction and is a permanent bleaching process.

How sulphur dioxide is prepared in laboratory explain the bleaching property of sulphur dioxide?

Preparation of Sulphur Dioxide In the laboratory, sulphur dioxide is prepared by the reaction of metallic sulphite or a metallic bisulphite with dilute acid. For example, a reaction between the dilute sulphuric acid and sodium sulphite will result in the formation of SO2.

Which is correct about bleaching action of ozone and sulphur dioxide?

Bleaching action of ozone is based on oxidation while that of sulphur is based on reduction. Ozone produce oxygen and nascent oxygen. This nascent oxygen bleaches the colour permanently.

Is sulphur dioxide a bleaching agent?

Sulphur dioxide acts as a temporary bleaching agent and removes oxygen by reduction as mentioned in the above reaction.

Why chlorine is a powerful bleaching agent?

Explanation: Chlorine react with water to form Hypochlorous acid along with Hydrochloric acid,as Hypochlorous acid is very unstable,it release nascent oxygen along with hydrochloric acid ,these nascent oxygen is a powerful beaching agent,and responsible for the bleaching action in Cl2.

Which shows bleaching due to reduction?

Bleaching property of chlorine is due to oxidation whereas the bleaching property of sulphur dioxide is due to reduction. Sulphur dioxide acts as a temporary bleaching agent and removes oxygen by reduction as mentioned in the above reaction.

How Sulphur dioxide is prepared in laboratory explain the bleaching property of Sulphur dioxide?

How does Sulphur dioxide bleach things?

Sulphur dioxide acts as a temporary bleaching agent and removes oxygen by reduction as mentioned in the above reaction. Therefore Sulphur dioxide removes oxygen from the colored substances and makes them colorless through reduction process but it is a temporary action.

What compound is formed when sulphur dioxide is passed through water a sulphuric acid C hydrogen sulphide B sulphurous acid D sulphur trioxide?

When sulphur dioxide is dissolved in water it forms sulphurous acid.

Is sulfur dioxide a bleaching agent?

Everybody knows chlorine (C l X 2) is a bleaching agent acting on oxidation. However, what majority of us do not know is sulfur dioxide (S O X 2) is also a bleaching agent, which in contrast to C l X 2, acting on reduction (though we know about other reducing sulfur agents such as sodium dithionite and thiosulfate).

What is the difference between chlorine and sulfur dioxide bleaches?

Basically, chlorine bleaches knock off electrons, whereas sulfur dioxide bleaches add electrons to the chromophores thus inhibiting their colour-related capabilities. Pigment is usually a complex molecule that gains its properties much like proteins do — by their unique shapes.

Why is the bleaching action of chlorine permanent?

The bleaching action of Chlorine is permanent because it involves the process of oxidation. Chlorine reacts with water to produce nascent oxygen. This oxygen combines with the colours material and makes it colourless. It a powerful oxidising agent.

What happens when hypochlorous acid is mixed with sulphur di oxide?

Hypochlorous acid is unstable, and it easily dissociates to form nascent oxygen. The bleaching action of sulphur di oxide is temporary because it involves the process of reduction. sulphur di oxide removes oxygen from the coloured substance and makes it colourless.