question_answer

The \[BC{{l}_{3}}\] is a planar molecule whereas \[NC{{l}_{3}}\]is pyramidal, because

A)  nitrogen atom is smaller than boron atoms

B)  B?Cl bond is more polar than N?Cl bond

C)  N?Cl bond is more covalent than B?Cl bond

D)  \[FC{{l}_{3}}\] has no lone pair but \[NC{{l}_{3}}\] has a lone pair of electrons

Correct Answer: D

Solution :

                 In boron trichloride, boron is \[s{{p}^{2}}\] hybridised and there is no lone pair on boron hence, \[BC{{l}_{3}}\] is planar in shape while in \[NC{{l}_{3}}\] the nitrogen is \[s{{p}^{3}}\] hybridised and there is a lone pair on nitrogen atom hence, the shape of \[NC{{l}_{3}}\] is pyramidal.                 Trigonal planar geometry of \[BC{{l}_{3}}\] molecule                                 Pyramidal shape of \[NC{{l}_{3}}\] is molecule