Class 12 NEET Chemistry D And F Block Elements Questions

Concept:Transition metals and their compounds act as catalysts in many industrial and laboratory reactions because of their variable oxidation states and their ability to adsorb reactants on their surfaces.Chemical Equations / Formulae:$2\mathrm{SO_2} + \mathrm{O_2} \xrightarrow{\mathrm{V_2O_5}} 2\mathrm{SO_3}$$\mathrm{N_2} + 3\mathrm{H_2} \xrightarrow{\mathrm{Fe}} 2\mathrm{NH_3}$$\mathrm{HC \equiv CH} + \mathrm{H_2O} \xrightarrow{\mathrm{PdCl_2}} \mathrm{CH_3CHO}$$n\,\mathrm{HC \equiv CH} \xrightarrow{\text{Ni complex}} \text{Polymer}$Explanation:$\mathrm{V_2O_5}$ catalyses the oxidation of $\mathrm{SO_2}$ to $\mathrm{SO_3}$ in the Contact process, which is used for the manufacture of $\mathrm{H_2SO_4}$.So A is matched with III.Fe is the catalyst in the Haber–Bosch process for the synthesis of ammonia from a $\mathrm{N_2}/\mathrm{H_2}$ mixture.So B is matched with I.$\mathrm{PdCl_2}$ catalyses the oxidation of ethyne to ethanal (Wacker-type oxidation).So C is matched with IV.A nickel complex catalyses the polymerisation of alkynes.So D is matched with II.Answer:A-III, B-I, C-IV, D-II.This corresponds to option D (option D).