Hydrogen Sulphide -UPSC Current Affairs

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Context

Eleven people, died after allegedly inhaling toxic gas in Ludhiana.
High levels of Hydrogen Sulphide was detected in the air and authorities suspecting that it emanated from a sewer.

Hydrogen sulfide: Fast Facts

Properties

Hydrogen sulfide is a chemical compound with the formula H2S.
It is a colorless chalcogen-hydride gas.
It is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs.
Hydrogen sulfide is slightly denser than air. A mixture of H2S and air can be explosive.
In general, hydrogen sulfide acts as a reducing agent.

Discovery

Swedish chemist Carl Wilhelm Scheele is credited with having discovered the chemical composition of purified hydrogen sulfide in 1777.

Effects

Hydrogen sulfide is toxic to humans and most other animals by inhibiting cellular respiration. When it is inhaled or its salts are ingested in high amounts, damage to organs occurs rapidly with symptoms ranging from breathing difficulties to convulsions and death.
Despite this, the human body produces small amounts of this sulfide and its mineral salts, and uses it as a signaling molecule.

Sources

Hydrogen sulfide is often produced from the microbial breakdown of organic matter in the absence of oxygen, such as in swamps and sewers; this process is commonly known as anaerobic digestion, which is done by sulfate-reducing microorganisms.
It also occurs in volcanic gases, natural gas deposits, and sometimes in well-drawn water.
It can also be associated with animal farms, industrial plants, sewers or sewage treatment plants.

PRACTICE QUESTION

Q. Which of the following statements are correct?

a) Hydrogen sulfide is slightly lighter than air.

b) It occurs in volcanic gases, natural gas deposits, and sometimes in well-drawn water.

c) Hydrogen sulfide is toxic to humans and most other animals by inhibiting cellular respiration.

d) In general, hydrogen sulfide acts as an oxidizing agent.

1. a and b only

2. b and c only

3. c and d only

4. All of the above statements are correct.

Correct Answer: Option 2