There are two important fuels A and B both of which are extracted from deep inside the earth. Fuel A is a thick, dark, foul smelling liquid whereas fuel B is a black solid. Combustion of both the fuels produces products, C, D, E and F. The product C makes the rainwater only slightly acidic but it is mainly responsible for causing global warming. The product D is neither acidic nor basic. It is harmless and does not affect the environment in any way. Both E and F attack breathing system of humans and are mainly responsible for causing acid rain. In addition to combustion of fuels A and B, the product F is also formed when lightning occurs in the sky. (a) What are (i) fuel A, and (ii) fuel B ? (b) Name (i) C (ii) D (iii) E, and (iv) F (c) What is the process of formation of F during lightning known as ? (d) Which fuel is supposed to be exhausted sooner : A or B ? (e) Which fuel is mostly used for generating electricity at thermal power plants ?

There are two important fuels A and B both of which are extracted from deep inside the earth. Fuel A is a thick, dark, foul smelling liquid whereas fuel B is a black solid. Combustion of both the fuels produces products, C, D, E and F. The product C makes the rainwater only slightly acidic but it is mainly responsible for causing global warming. The product D is neither acidic nor basic. It is harmless and does not affect the environment in any way. Both E and F attack breathing system of humans and are mainly responsible for causing acid rain. In addition to combustion of fuels A and B, the product F is also formed when lightning occurs in the sky.
(a) What are (i) fuel A, and (ii) fuel B ? (b) Name (i) C (ii) D (iii) E, and (iv) F

(c) What is the process of formation of F during lightning known as ?

(d) Which fuel is supposed to be exhausted sooner : A or B ?

(e) Which fuel is mostly used for generating electricity at thermal power plants ?

(a) The two important fossil fuels are coal and petroleum. Coal is a black solid while petroleum is a thick, dark, foul smelling liquid. So, (i) Petroleum (ii) Coal

(b) The products of combustion are water, carbon dioxise, sulphur dioxide and nitrogen oxides. Water is neither acidic nor basic and doesn’t even harm the environment so water is D. Carbon dioxide makes the rain water only slightly acidic and is mainly responsible for causing global warming so carbon dioxide is C. E and F which are mainly responsible for causing acid rain should be sulphur dioxide and nitrogen oxides respectively. It is so because nitrogen oxide is also formed when lightning occurs in the sky.

(c) The process of formation of nitrogen oxides when lightning occurs in the sky is known as N atural fixation of nitrogen.

(d) Between coal and petroleum, A (Petroleum) is expected to exhaust sooner.

(e) Between coal and petroleum, B (Coal) is used for generating electricity at thermal power plants.