Question

Methyl isocyanate of Bhopal tragedy was
A. Carbamate
B. Organophosphate
C. Organochlorine
D. None of the above

Answer 1

Hint: 1)Bhopal gas tragedy happened at the Union Carbide India Limited, a pesticide plant in Bhopal.
2)Methyl isocyanate has a molecular formula $CH_3NCO$

Complete answer:
Option A: Carbamate is an organic compound derived from carbamic acid, by replacing a hydrogen atom with any other functional group. Methyl isocyanate is an intermediate compound in carbamate pesticide production. Methyl isocyanate is colorless, flammable and highly poisonous, and extremely toxic to humans. Exposure to them can cause chest pain, asthma which will lead to lung edema, bronchial pneumonia, and eventually death. Therefore this is the correct answer.

Option B: Organophosphates are compounds with a phosphorus molecule with an alkyl or aromatic substituents attached to it. Some forms of organophosphates are found in DNA, RNA, etc but some of them are poisonous. They act as a nerve agent that inhibits the action of acetylcholine. They constitute 50% of today’s pesticides used. Methyl isocyanate is not an organophosphate. Therefore, this is the incorrect option.

Option C: Organochlorine are organic compounds with at least one chlorine atom which is covalently bound and affects the property of the compound. They are found in biomolecules such as terpene, steroids, etc. They are components of pesticides like DDT and can affect the nervous system. Methyl isocyanate doesn't contain chlorine. Therefore, this is the incorrect option.

Option D: Carbamate is the correct answer. Therefore, this is the incorrect option.

Hence, the correct answer is option (A)

Note: The Bhopal gas tragedy happened on 2-3 December 1948. Over 500,000 people were exposed to the methyl isocyanate(MIC) gas leaked from the UCIL pesticide factory and nearly 2,259 were killed. In this plant, methylamine was reacted with phosgene to form MIC intermediate which then reacts with naphthol to form carbaryl, the final product.