Question

Decreasing order of bond angle in bf3 ,nh3,pf3,i3-

Answer 1

I3− > BF3 > NH3 > PF3

Reason:

Hybridization: Bond point relies upon the condition of hybridization of an atom.  In general, s-character decreases in hybridized bond, the bond angle decreases.  

Repulsion of lone pair: Bond angle is influenced by the nearness of lone pair of electrons at an atom. The lone pair electrons at the atom attempts to repulse the bonded pair of electrons. Because of this, the bonds are slightly disorganized inside and results in decrease of bond angle.

Electronegativity: If the electronegativity of an atom decreased, the bond angle will decrease.

Answer 2

I3− > BF3 > NH3 > PF3

Reason:

Hybridization: Bond point relies upon the condition of hybridization of an atom.  In general, s-character decreases in hybridized bond, the bond angle decreases.  

Repulsion of lone pair: Bond angle is influenced by the nearness of lone pair of electrons at an atom. The lone pair electrons at the atom attempts to repulse the bonded pair of electrons. Because of this, the bonds are slightly disorganized inside and results in decrease of bond angle.

Electronegativity: If the electronegativity of an atom decreased, the bond angle will decrease.