Question

Arrange the following sets of molecules in the decreasing order of bond angle – 

(i) SF₆, H₂O, NH₃, CH₄ 

(ii)  NH₃,CH₄, BF₃, BeCl₂

(iii) BeH₂, H₂O, AlCl₃, H₂S

Answer 1

(i) Decreasing order of bond angle:

CH₄ (109.5º)(Tetrahedral) > NH₃ (107º) (Pyramida) > H₂O (104.5º) (Angular) > SF₆ (90º) (Octahedral)

(ii) Decreasing order of bond angle:

BeCl₂ (108º) (Linear) > BF₃ (120º) (Planar) > CH₄ (109.5º) (Tetrahedral) > NH₃ (107º) (Pyramidal)

(iii) Decreasing order of bond angle:

BeH₂ (108º) (Linear) > AlCl₃ (120º) (Planar) > H₂O (104.5º) (Angular) > H₂S (100º) ((Angular but S is less electronegative than O)