Hydrogenation of alkenes and alkynes takes place in presence of certain catalysts. In Sabatier Senderen's reaction, the addition of hydrogen takes place I presence of Raney nickel catalyst. Platininm and palladium can also be used as catalyst and used in finley divided state. Experimentally, it is observed that less crowded alkenes adsorb H_(2) with faster rate. Controlled hydrogenation of alkyne H_(2) with faster rate. Controlled hydrognetation of alkyne in presence of Lindlar's catalyst yields cis producti.e.,'cis' alkene. Thus, in presence of Lindlar's catalyst 'syn' addition takes place. The relative rate of hydrogenation follows the order: Non-terminal alkynes are reduced in presence of Na or Li metal dissolved in liquid ammonia. In this reaction, anti-addition of hydrogen results into the trans-product. Powdered nickel is more effective than grannular nickel because:

Hydrogenation of alkenes and alkynes takes place in presence of certai

1.	Hydrogenation of alkenes and alkynes takes place in presence of certain catalysts. In Sabatier Senderen's reaction, the addition of hydrogen takes place I presence of Raney nickel catalyst. Platininm and palladium can also be used as catalyst and used in finley divided state. Experimentally, it is observed that less crowded alkenes adsorb H_(2) with faster rate. Controlled hydrogenation of alkyne H_(2) with faster rate. Controlled hydrognetation of alkyne in presence of Lindlar's catalyst yields cis producti.e.,'cis' alkene. Thus, in presence of Lindlar's catalyst 'syn' addition takes place. The relative rate of hydrogenation follows the order: Non-terminal alkynes are reduced in presence of Na or Li metal dissolved in liquid ammonia. In this reaction, anti-addition of hydrogen results into the trans-product. Powdered nickel is more effective than grannular nickel because:
Answer» Surface AREA of powdered nickel is maximum Free VALENCIES are LARGE in number Powdered nickel increases the activation energy of the reaction. Powdered nickel increases the intermolecular collision of REACTANT molecules. Solution :N//A