Question

Which of the following are not fumigants? A. Aluminium phosphide, B. Carbofuran, C. Hydrogen cyanide, D. Chlorpyriphos.

• A. A and C Only
• B. B and D Only
• C. A, B and C Only
• D. C and D Only

Hint:

Aluminium phosphide and hydrogen cyanide are fumigants, while carbofuran and chlorpyriphos are not fumigants.

Answer 1

The Correct Option is B

Fumigants are pesticides that work in the form of toxic gases to control pests in stored grains, soil, warehouses, etc.

Let's analyze each compound:

• A. Aluminium phosphide 
  It releases phosphine gas on contact with moisture: $$\text{AlP} + 3H_2O \rightarrow Al(OH)_3 + PH_3$$ Phosphine gas \((PH_3)\) is highly toxic and used as a fumigant. 
  So, it is a fumigant.
• B. Carbofuran 
  Carbofuran is a carbamate insecticide used mainly in soil and crops. It is not used in gaseous form. 
  So, it is not a fumigant.
• C. Hydrogen cyanide 
  Hydrogen cyanide \((HCN)\) is a toxic gas historically used as a fumigant. 
  So, it is a fumigant.
• D. Chlorpyriphos 
  Chlorpyriphos is an organophosphate insecticide used as spray or soil treatment, not as a fumigant gas. 
  So, it is not a fumigant.

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Therefore, the substances that are not fumigants are:

$$\boxed{\text{B and D Only}}$$