Which of the following statements are correct?

A. p-Nitroaniline is a stronger base than aniline

B. Aniline is weaker basic than o-nitro aniline

C. Aniline is a weaker base than ethylamine

D. p-methyoxyaniline is stronger base than aniline

E. Aniline is weaker base than ammonia

Choose the correct answer from the options given below:

E, C and D only

The correct answer is option 1. E, C and D only.

Let us look at each of these statements:

A. p-Nitroaniline is a stronger base than aniline: This statement is incorrect6. Nitro groups \((-NO_2)\) are electron-withdrawing, reducing the availability of the lone pair on nitrogen for accepting a proton. Thus, p-nitroaniline is a weaker base than aniline.

B. Aniline is weaker basic than o-nitro aniline: This statement is incorrect. Ortho-substituents can interfere with the conjugation between the lone pair on nitrogen and the aromatic ring in aniline. This reduces the delocalization of the lone pair, making it more available for accepting a proton. Therefore, o-nitroaniline is a weaker base than aniline.

C. Aniline is a weaker base than ethylamine: This statement is correct. Aromatic amines like aniline have their lone pair delocalized into the aromatic ring, making it less available for accepting a proton. In contrast, ethylamine (an aliphatic amine) has a more localized lone pair, leading to greater basicity.

D. p-methyoxyaniline is stronger base than aniline: This statement is correct. Methoxy groups \((-OCH_3)\) are electron-donating, increasing the electron density on the nitrogen atom. This makes the lone pair more available for accepting a proton, enhancing the basicity of p-methyoxyaniline compared to aniline.

E. Aniline is weaker base than ammonia: This statement is correct. Similar to aliphatic amines, ammonia has a more localized lone pair on nitrogen, making it a stronger base than aniline.