Iron filings and sulphur were mixed together and divided into two parts, ‘A’ and ‘B’. Part ‘A’ was heated strongly, while Part ‘B’ was not heated. Dilute hydrochloric acid was added to both Parts and the evolution of gas was seen in both cases. How will you identify the gases evolved?
ScienceClass 9CBSEAnswered 27 Mar 2026
Answer
Solution:
When iron fillings and sulphur is heated, it will give the following reaction
Fe(s)+S(s) → FeS
When HCl is added to this mixture, ferric chloride is produced, and Hydrogen Sulphide gas is produced. A foul rotten egg smell of Hydrogen sulphide is the indicator of H2S production.
When dilute HCL is added to setup B, Hydrogen gas is evolved, and sulphur does not take part in the reaction. When a burning matchstick is brought near the evolved gas, the matchstick burns with a pop. This is the indication of the production of Hydrogen gas.
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