Reduction of an alkyne to the double bond stage can yield a cis alkene or trans alkene (except in cases where triple bond is at the end of the chain ) Reduction of alknes with sodium or lithium in liquid NH_(3) yields predominantly trans alkene. Hydrogenation of alkynes with Lindlar's catalyst or a nickel boride called P_(2) catalyst yeilds is alkene (as high as 98%) If Pd/C/H_(2) is used in the absence of a catalyst poison, two equivlanet of H_(2) are added forming alkanes.Lindlar's catalyst can be prepared in precipitating palladium calcium carbonate and treating it with lead acetate or quinoline. This treatement is

Reduction of an alkyne to the double bond stage can yield a cis alkene

1.	Reduction of an alkyne to the double bond stage can yield a cis alkene or trans alkene (except in cases where triple bond is at the end of the chain ) Reduction of alknes with sodium or lithium in liquid NH_(3) yields predominantly trans alkene. Hydrogenation of alkynes with Lindlar's catalyst or a nickel boride called P_(2) catalyst yeilds is alkene (as high as 98%) If Pd/C/H_(2) is used in the absence of a catalyst poison, two equivlanet of H_(2) are added forming alkanes.Lindlar's catalyst can be prepared in precipitating palladium calcium carbonate and treating it with lead acetate or quinoline. This treatement is
Answer» partically deactivities the catalyst WHICHCAUSES REDUCTION of ALKYNE to alkene increases the rate of hydogention selectively gives only cis-isomer selectively gives trans-isomer Answer :C