question_answer 137)

  A reaction between ammonia and boron trifluoride is given below: \[B{{F}_{3}}+\,_{\centerdot }^{\centerdot }N{{H}_{3}}\to {{H}_{3}}N_{\centerdot }^{\centerdot }B{{F}_{3}}\] Identify the acid and base in this reaction. Which theory explains it? What is the hybridization of B and N in the reactants?                

Answer:

  In the reaction: \[\underset{(s{{p}^{2}})}{\mathop{B{{F}_{3}}}}\,+\,\underset{(s{{p}^{3}})}{\mathop{_{\centerdot }^{\centerdot }N{{H}_{3}}}}\,\to H-\overset{\overset{H}{\mathop{|}}\,}{\mathop{\underset{\underset{\text{H}}{\mathop{\left| s{{p}^{3}} \right.}}\,}{\mathop{N_{\centerdot }^{\centerdot }}}\,}}\,\to \overset{\overset{\text{F}}{\mathop{\text{ }\!\!|\!\!\text{ }}}\,}{\mathop{\underset{\underset{\text{F}}{\mathop{\left| \text{s}{{\text{p}}^{\text{3}}} \right.}}\,}{\mathop{\text{B}}}\,}}\,-F\] According to Lewis Acid-Base theory: \[N{{H}_{3}}\to \] Lewis Base (Electron pair donor) \[B{{F}_{3}}\to \] Lewis Acid (Electron pair acceptor)