Question

The petroleum product that has replaced coal-tar for metalling the road is _________.
A. peat
B. bitumen
C. lignite
D. anthracite

Answer 1

Petroleum product are the substances obtained from crude oil in petroleum refineries. Coal tar is one of the byproducts of coke and coal gas from coal. Metalling of roads means applying broken stone or cinders to the road for repairing of roads and railways.

Complete step by step answer:
The petroleum product that has replaced coal tar for metalling the road is bitumen. Bitumen provides better grip with the tires of vehicles than coal tar which readily heats up and the tires of vehicles are damaged by the heat. Bitumen is composed of complex hydrocarbon obtained from petroleum refining. The elements present in it are iron, calcium, sulfur and oxygen. It is also known as asphalt found as black, sticky and highly viscous liquid. They are primarily used for paving roads and making waterproofing.
Peat: Peat is an organic matter obtained by partial decay of vegetables. These are fully derived from plant sources and serve as carbon sinks of the planet. They are harvested as a fuel source for different parts of the world. Peatland plants absorb carbon dioxide from the atmosphere thus maintain the equilibrium with the surroundings.
Lignite: Lignite is formed by naturally compressed peat. They are combustible minerals and are low in heat content. They are used for generating electricity and are very cost effective.
Anthracite: Anthracite is referred to as hard coal as it has the highest carbon content. This form of coal has metallic luster. They are also used for power generation in high grade and ultra grade mode.

Hence option B is the correct answer, i.e. bitumen.

Note:
Bitumen has waterproofing and adhesive properties. When mixed with broken stones they serve as binder and hold the surface of roads strongly.