Which allotropic form of sulfur is used as an insecticide and acaricide in agriculture?
Rhombic sulfur
Monoclinic sulfur
Amorphous sulfur
Plastic sulfur
Option A Rhombic sulfur is the most common form of sulfur and is used as an insecticide and acaricide in agriculture. It is a yellow, crystalline solid that is stable at room temperature and pressure. Rhombic sulfur has a melting point of and a boiling point of .
Explanation of incorrect option
incorrect option B Monoclinic sulfur is a less stable form of sulfur that can be obtained by cooling molten sulfur slowly. It has a melting point of and is less commonly used in agriculture.
incorrect option C Amorphous sulfur is a non-crystalline form of sulfur that lacks a definite shape or structure. It is usually produced by heating sulfur to a high temperature and cooling it rapidly. Amorphous sulfur is not commonly used in agriculture.
incorrect option D Plastic sulfur is a metastable form of sulfur that is obtained by heating rhombic sulfur above its melting point and cooling it rapidly. It is a soft, elastic solid that can be molded like plastic. Plastic sulfur is not commonly used in agriculture.