Roasting of sulphides gives the gas X as a by-product. This is a colorless gas with choking smell of burnt sulphur and causes great damage to respiratory organs as a result of acid rain. Its aqueous solution is acidic acts as a reducing agent and its acid has never been isolated. The gas X is

Question

Which of the following oxoacids of sulphur contains \(S\) in two different oxidation states?

Answer 1

The gas produced during the roasting of sulphide ores is sulfur dioxide (SO₂). Let's go through the reasoning step-by-step:

Roasting of sulfide ores generally involves heating the ore in the presence of oxygen. This process converts the metal sulfide into metal oxide, with sulfur dioxide as a by-product.
The chemical reaction for the roasting of a generic metal sulfide (MS) is: MS + O_2 \rightarrow MO + SO_2 where M represents a metal.
Sulfur dioxide (SO₂) is known for its characteristic properties:
- It is a colorless gas with a pungent smell, often described as the smell of burnt sulfur.
- SO₂ is a major pollutant that contributes to acid rain, which can cause damage to respiratory organs and the environment.
- An aqueous solution of SO₂ forms sulfurous acid (H₂SO₃), which acts as a reducing agent.
- Sulfurous acid cannot be isolated in a pure form, as it exists only in solution.
Considering the other options:
- H₂S (hydrogen sulfide) is a colorless gas but with a characteristic rotten egg smell, not a choking smell.
- CO₂ (carbon dioxide) is also colorless but does not have the properties described in the question.
- SO₃ (sulfur trioxide) is not typically produced by roasting sulfide ores. It is often associated with the formation of sulfuric acid when combined with water.

Given these observations, the gas X is indeed sulfur dioxide (SO₂).

Answer 2

The gas produced during the roasting of sulphide ores is sulfur dioxide (SO₂). Let's go through the reasoning step-by-step:

Roasting of sulfide ores generally involves heating the ore in the presence of oxygen. This process converts the metal sulfide into metal oxide, with sulfur dioxide as a by-product.
The chemical reaction for the roasting of a generic metal sulfide (MS) is: MS + O_2 \rightarrow MO + SO_2 where M represents a metal.
Sulfur dioxide (SO₂) is known for its characteristic properties:
- It is a colorless gas with a pungent smell, often described as the smell of burnt sulfur.
- SO₂ is a major pollutant that contributes to acid rain, which can cause damage to respiratory organs and the environment.
- An aqueous solution of SO₂ forms sulfurous acid (H₂SO₃), which acts as a reducing agent.
- Sulfurous acid cannot be isolated in a pure form, as it exists only in solution.
Considering the other options:
- H₂S (hydrogen sulfide) is a colorless gas but with a characteristic rotten egg smell, not a choking smell.
- CO₂ (carbon dioxide) is also colorless but does not have the properties described in the question.
- SO₃ (sulfur trioxide) is not typically produced by roasting sulfide ores. It is often associated with the formation of sulfuric acid when combined with water.

Given these observations, the gas X is indeed sulfur dioxide (SO₂).

The Correct Option is B