Identify correct decreasing order of basic strength of amines

Step-by-step solution

Basic strength of amines depends on the availability of the lone pair of electrons on the nitrogen atom for protonation. In aliphatic amines, the electron-donating +I effect of alkyl groups increases the electron density on nitrogen, making them more basic than ammonia. For methylamines in aqueous solution, the combined effect of the +I effect, steric hindrance, and hydration energy results in the basic strength order: secondary > primary > tertiary. Thus, ( CH ₃)₂ NH > CH ₃ NH ₂ > NH ₃ . In aniline ( C ₆ H ₅ NH ₂