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For the conversion of alkyne to cis-alke...

For the conversion of alkyne to cis-alkene, `H_2+` Lindlar's catalyst is used:

Which of the statements are wrong:

A

(a) The function of `BaSO_4` or `CaCO_3` is to reduce the surface area of finely divided catalyst Pd so that adsorption of `H_2` on `Pd` is reduced.

B

(b) The function of S or quinoline is to remove excess of `H_2`. It is done through the formation of `H_2S(g)` with S or by absorption of excess `H_2` by quinoline to form (I) or (II).

C

(c) Boiling xylene acts as a solvent to dissolve the reactant (alkyne).

D

(d) Boiling xylene acts as inhibitor, decreasing the asborption of `H_2` on finely divided catalyst `Pd` or `Pt`.

Text Solution

Verified by Experts

The correct Answer is:
D
Compound III is chiral and shows optical isomerism. Statements a, b, and c are self explanatory.
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Knowledge Check

  • Which statement is wrong about H_2O ?

    A
    It has high specific heat relative to other liquids or solids due to strong intermolecular H-bonding
    B
    `H_2O` molecule has capaity to form ` 4H`-bonds
    C
    `H_2O` has open cage like structure due to intermolecular H-bonding which give rise to low density to ice than liquid `H_2O`
    D
    `H_2O` has maximum density at `4^@ C` since upto `4^@C` the intermolecular H-bonding persists more and thereby decreasing volume and increasing density .

  • The reduction of 3-hexyne with H_(2) /Lindlar’s catalyst gives predominantly -

    A
    n-Hexane
    B
    Trans-3-hexene
    C
    Cis-3-hexene
    D
    A mixture of cis-and trans-3-hexene

  • 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 product i.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:

    A
    Surface area of powdered nickel is maximum
    B
    Free valencies are large in number
    C
    Powdered nickel increases the activation energy of the reaction.
    D
    Powdered nickel increases the intermolecular collision of reactant molecules.

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    Hydrogenation of alkenes and alkynes takes place in presence of certain catalysts. In sabatier-Senderen's reaction, the addition of hydrongen taken place in presence of nickel catalyst. Controlled hydrogenation of alkyne in presence of Lindlar's catalyst gives cis-alkene. Non terminal alkynes are reduced by Na or Li metal dissolved in liquid NH_(3) . In this reaction trans alkenes are formed. Q. In which of the following the reaction is most exothermic

    Hydrogenation of alkenes and alkynes takes place in presence of certain catalysts. In sabatier-Senderen's reaction, the addition of hydrongen taken place in presence of nickel catalyst. Controlled hydrogenation of alkyne in presence of Lindlar's catalyst gives cis-alkene. Non terminal alkynes are reduced by Na or Li metal dissolved in liquid NH_(3) . In this reaction trans alkenes are formed. Q. The product of the following reaction is

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    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 hydrogenation of alkyne in presence of Lindlar's catalyst yields cis product i.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. H_(3)C-C-=C-CH_(3)+H_(2) overset(Pd//CaCO_(3))underset("Boiling Quinoline")to (A) The product (A) will be:

    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 hydrogenation of alkyne in presence of Lindlar's catalyst yields cis product i.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. Answer the following questions: The relative rate of catalytic hydrogenation of following alkenes is:

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