What do you understand by the terms:
(i) hydrogen economy
(ii) hydrogenation
(iii) syngas
(iv) water-gas shift reaction
(v) fuel-cell

Explanation

a. Hydrogen economy
b. Hydrogenation
c. Syngas
d. Water-gas shift reaction
e. Fuel cell: A device which converts the energy produced during the combustion of a fuel directly into electrical energy is known as fuel cell. Dihydrogen is used in hydrogen-oxygen fuel cells for generating electrical energy. Fuel cell has many advantages over the conventional fossil fuels. It does not cause any pollution and releases more amount of energy per unit mass of fuel as compared to gasoline and other fuels.