881.

The bond angle in NF₃ (102.3°) is, smaller than NH₃ (107.2°). This is because of

• large size of F compared to H

• large size of N compared to F

• opposite polarity of N in the two molecules

• small size of H compared to N

The structure of XeF₆ is experimentally determined to be distorted octahedron. Its structure according to VSEPR theory is

• octahedron

• trigonal bipyramid

• pentagonal bipyramid

• tetragonal bipyramid

XeF₂ is isostructural with

• TeF₂

• ICl₂^-

• SbCl₃

• BaCl₂

In the following electron-dot structure calculate the formal charge from left to right nitrogen atom; $\stackrel{\mathbf{.}\mathbf{.}}{\underset{\mathbf{.}\mathbf{.}}{\mathrm{N}}}=\mathrm{N}=\stackrel{\mathbf{.}\mathbf{.}}{\underset{\mathbf{.}\mathbf{.}}{\mathrm{N}}}$ :

• -1 , -1 , +1

• -1 , +1 , -1

• +1 , -1 , -1

• +1 , -1 , +1

The sp³d² hybridisation of central atom of a molecule would lead to:

• square planar geometry

• tetrahedral geometry

• trigonal bipyramidal geometry

• octahedral geometry

Which one of the following molecules contain no $\mathrm{\pi }$-bond?

• CO₂

• H₂O

• SO₂

• NO₂

Why B₂ is paramagnetic whereas C₂ is dimagnetic?

Dipole moment of  is 1.5 D. The dipole moment of  is

• 1.5 D

• 2.25 D

• 1 D

• 3 D

The hybridisation of C₂ and C₃ of H₃C-CH=C=CH-CH₃ are:

• sp , sp³

• sp² , sp

• sp² , sp²

• sp , sp

Hybridisation of central atom in NF₃ is

• sp³

• sp

• sp²

• dsp²