(i)-(c), (ii)-(d), (iii)-(b), (iv)-(e), (v)-(a)

(i)-(c) Hydrogenation of vegetable oil to ghee needs a catalyst and Ni in the presence of hydrogen acts as the catalyst

(ii)-(d) Copper salts are used as reagents and catalysts in Sandmeyer reaction, where diazonium salts are converted to aryl halides.

(iii)-(b) Contact process is the method used to produce sulphuric acid and V₂O₅ is used as a catalyst for the reaction.

(iv)-(e) Haber’s process is used in the manufacturing of ammonia. Finely divided iron is used as a catalyst for the reaction.

(v)-(a) Ziegler Natta catalyst is used in the synthesis of polymers from 1-alkenes. It usually consists of TiCl₄ with an aluminium based co-catalyst.