The increasing order of the acidity of the following carboxylic acids 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 ?

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

Which of the following best describes the diagram below of a molecular orbital ?