Q.Complete the chart. Name the catalyst used in: Hydrogenation of oil (Hardening).

Using a catalyst speeds up a chemical reaction's rate without the catalyst itself being permanently consumed. Catalysts help in three connected ways: they increase a reaction's selectivity toward the desired product, they minimise waste (since a more selective reaction produces less unwanted byproduct), and they reduce both reaction times and energy demands by lowering the activation-energy barrier a reaction has to overcome. Because a catalyst is regenerated rather than consumed, a small amount can process a very large amount of reactant over time, making catalytic routes far more atom- and energy-efficient than stoichiometric ones. Well-known industrial examples include finely divided iron (promoted with K2O/Al2O3) in the Haber process for ammonia, vanadium pentoxide (V2O5) in the Contact process for sulfuric acid, Ziegler-Natta catalysts for HDPE manufacture, nickel for hydrogenating (hardening) vegetable oils, and cobalt- or iron-based catalysts in the Fischer-Tropsch process for synthesising gasoline-range hydrocarbons from syngas -- reactions the chapter's own 'Complete the Chart' activity asks students to match to their catalysts from prior chemistry knowledge.