On treatment of the following compound with a strong acid, the most susceptible site for bond cleavage is :

When 2-butyne is treate with H₂/Lindlar's catalyst, compound X is produced as the major product and when treated with Na/liq. NH₃ it produces Y as the major product Which of the following statements is correct ?

The increasing order of the acidity of the following carboxylic acids is :

The total number of possible isomers for square-planar [Pt(Cl)(NO₂)(NO₃)(SCN)]^2- is :