13.4 Arrange the following in increasing order of their basic strength: 

(i) C₂H₅NH₂, C₆H₅NH₂, NH₃, C₆H₅CH₂NH₂ and (C₂H₅)₂NH

(ii) C₂H₅NH₂, (C₂H₅ )₂NH, (C₂H₅ )₃N, C₆H₅NH₂

(iii) CH₃NH₂, (CH₃ )₂NH, (CH₃)₃N, C₆H₅NH₂, C₆H₅CH₂ NH₂ .

<p><strong>1- </strong>Alkyl group contribute inductive effect which increases the basic strength of</p><p>NH₃&lt;c_{2H5NH2&lt; (C2H5)2NH.&lt;/c}</p><p>Then C₆H₅NH₂ is having –I effect that reduces strength. And C₆H₅CH₂NH₂ increases the basic strength but not as much as C₂H₅ group.</p><p>Hence final order will be C₆H₅NH₂&lt;&lt;nh_{3&lt;c6H5CH2NH2&lt;c2H5NH2&lt; (C2H5)2NH.&nbsp;&lt;/c&lt;/c&lt;/nh}</p><p><strong>2-</strong> By taking into consideration –R effect and steric hindrance of groups we can arrange them in the order</p><p>C₆H₅NH₂&lt; C₂H₅NH₂&lt; (C2H5)₃N&lt; (C₂H₅)₂NH.</p><p>Because (C₂H₅)₃N has a lot of steric hindrances that reduces the basic strength.</p><p><strong>3-</strong> In C₆H₅NH₂, N is directly attached to the ring that causes delocalization of electrons of the benzene ring. Whereas in case of C₆H₅CH₂NH₂ it is not directly connected to benzene ring Hence it has more basic strength.</p><p>Due to –I effect of (CH₃)₃ ^– a group it has more basic strength than C₆H₅CH₂NH₂. Hence final order will be</p><p>C₆H₅NH₂&lt; C₆H₅CH₂NH₂&lt; (CH₃)₃N&lt; CH₃NH₂&lt; (CH₃)₂NH</p>

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