Correct Option
The correct option isIt is the primary material used for metalling modern roads.
Explanation
Coal tar is a black, thick liquid with an unpleasant smell, obtained as a by-product during the processing of coal to manufacture coke. It is a complex mixture of approximately 200 carbon-based substances and serves as a raw material for various industries.
Statement-wise Analysis
- Statement It is used in the manufacture of synthetic dyes and drugs. is Correct: Products obtained from coal tar are used as starting materials for manufacturing various substances, including synthetic dyes, drugs, explosives, perfumes, plastics, paints, and photographic materials.
- Statement It is used in the production of roofing materials. is Correct: Coal tar is utilized in the production of roofing materials due to its binding and waterproofing properties.
- Statement It is the source of naphthalene balls. is Correct: Naphthalene balls, commonly used to repel moths and other insects, are obtained directly from coal tar.
- Statement It is the primary material used for metalling modern roads. is Incorrect: While coal tar was historically used for metalling roads, it has been largely replaced in modern times. Nowadays, Bitumen, a petroleum product, is the primary material used for metalling roads due to its superior durability and binding properties.
Key Takeaway: In modern road construction, Bitumen (a petroleum derivative) has replaced coal tar as the standard material for road metalling.