JEE MainChemistryIonic Equilibrium
The pK_ a values of the conjugate acids of four nitrogenous bases are 11.2 , 5.2 , 4.6 , and -3.8 . Which of the following compounds corresponds to the base whose conjugate acid has a pK_ a of -3.8 ?
Options
- APiperidine
- BAniline
- CPyridine
- DPyrrole
Correct answer
D. Pyrrole
Step-by-step solution
The strength of a base is inversely proportional to the strength of its conjugate acid. A lower pK_ a value for the conjugate acid indicates a stronger conjugate acid, and consequently, a weaker base. The pK_ a value of -3.8 is the lowest among the given values, meaning it corresponds to the weakest base. Let us evaluate the basicity of the given compounds: 1. Piperidine: It is a secondary aliphatic amine with a localized lone pair on an sp³ hybridized nitrogen, making it the strongest base. 2. Pyridine: The lone p