Question

The material A is fossil fuel which is extracted from the earth. It is said to be formed from the buried, large land plants by a very slow process B. when A is heated in the absence of air in a process called C, then it gives three products D, E and F. The product D is used as a reducing agent in the extraction of metals, the product E is used as an industrial fuel whereas the product F has been traditionally used for metallic the roads.

(a) What could material A be? 

(b) What is (i) physical state, and (ii) colour, of A? 

(c) Name the processes (i) B, and (ii) C. 

(d) What are (i) D, (ii) E, and (iii) F?

Answer 1

(a) The material A is Coal. Coal is a fossil fuel. It was formed by the process of carbonisation. Carbonisation is the process by which plant material or vegetation buried deep under the earth was slowly converted into coal. This is a very slow process and usually takes millions of years.

(b) Coal exists as solid. It is as hard as stone and is black in colour.

(c) The process B is carbonization. It is a process by which plant material or vegetation buried deep under the earth was slowly converted into coal. This is a very slow process and usually takes millions of years.

The process C is Destructive distillation. Destructive distillation is a chemical process of decomposition of a solid by heating it in a closed container. The volatile constituents produced in this process can be separated. Coal is processed in industry to get some useful products such as coke, coal tar and coal gas.

(d) The product D is coke, E is Coal gas and F is Coal tar. Coal is processed in industry by the process of destructive distillation to get some useful products such as coke, coal tar and coal gas. Coke is a tough, porous and black substance. It is almost pure form of carbon. Coal is a mixture of about 200 substances. It is a black, thick liquid with unpleasant smell. Coal gas is obtained during the processing of coal to get coke.