Chapter 22, Problem 56A

Interpretation Introduction

Interpretation- To order the given coal in terms of increasing carbon content.

Concept Introduction −

Coal is formed when decayed plants and animals form thick layers and eventually covered by layers of sand and rocks. This high pressure and heat due to which they convert to coal.

Coal can be classified based on hardness and carbon content as:

1. Peat
2. Lignite
3. Bituminous
4. Anthracite

Explanation of Solution

1. Peat: this is first stage of coal formation. It is very soft and has high water content while low carbon content.
2. Lignite: It is harder than peat with higher carbon content. $35\%to85\%$
3. Bituminous: It has lower water content and high carbon content than lignite nearly
4. Anthracite: When the pressure becomes intense, bituminous converts to anthracite which has highest carbon content, nearly $85\%$ .

Therefore, the order of increasing carbon content is peat>lignite>bituminous>anthracite