Question

Chemicals responsible for the Bhopal gas tragedy were

• A. ${CO}_2$ and ${CH}_4$
• B. phosgene and methyl isocyanate
• C. polychlorinated biphenyls
• D. dichloro diphenyl trichloroethane.

Answer 1

The correct option is B phosgene and methyl isocyanate

The Bhopal disaster or Bhopal gas tragedy was an industrial accident. It happened at a Union Carbide subsidiary pesticide plant in the city of Bhopal, India. On the night of 2-3 December 1984, the plant released approximately 40 tonnes of toxic methyl isocyanate (MIC) gas, exposing more than 500,000 people to toxic gases. The plant in Bhopal where the disaster happened started to produce 'Carbaryl' in 1977. Carbaryl is mainly used as an insecticide. The disaster happened because water entered a tank containing Methyl isocyanate. This caused a chemical reaction which resulted in the buildup of much Carbon dioxide, among other things. The resulting reaction increased the temperature inside the tank to reach over 200 °C (392 °F). The pressure was more than the tank was built to withstand. The tank had valves to control the pressure. These were triggered in an emergency, which reduced the pressure. As a result, large amounts of toxic gases were released into the environment.

So the correct option is 'phosgene and methyl isocyanate'.