Chemical Bonding and Molecular Structure

This is a Long Answer Type Questions as classified in NCERT Exemplar

Ans: Formation of N₂ molecule: Electronic Configuration

σ1s^{2 $<$} σ* < 1s² < 2s² < *2s² < [ 2p²_x = π2p²_y] < 2p²_z

The bond order will be:

$\frac{1}{2}$ ( 10-4)= 3.0

Bond order indicates the number of bonds in a diatomic molecule. Triple bond N=N.

Formation of F₂ molecule: Electronic Configuration

σ1s² < *1s²< 2s² < *2s²  < 2p²_z < [ 2p²_x = π2p²_y] < [ *2p²_x = π*2p²_y] σ*2p²_z

The bond order will be:

$\frac{1}{2}$ ( 10-10)= 0

Hence there will be no bond formation in between the neon atoms.

4.60. Lattice energy is defined as the energy released when one mole of crystalline solid is formed by the combination of oppositely charged ions.

(i)  As the magnitude of charge on an ion increases there will be greater force of interionic attraction and hence greater will be the value of Lattice energy,

(ii) Smaller the. size of the ions> lower will be the internuclear distance and thus greater will be the Lattice energy,

4.59. The outer shell electrons are shown as dots surrounding the symbol of the atom. These symbols are known as Lewis symbols or Lewis structures.

4.58.  (i) The molecule should contain highly electronegative atom like hydrogen atom.

(ii) The size of electronegative atom should be small.

4.57. Bonding molecular orbital has lower energy and higher stability.

4.56. Bond order of N₂ (= 3) is greater than that of O₂ (= 2).

4.55. N₂O is more polar than CO₂.

This is because CO₂ is linear and symmetrical. Its net dipole moment is zero.

N₂O is linear but not symmetrical.

4.54. This is because ethyl alcohol forms H-bonds with water.

4.53. The electron pairs involved in the bond formation are known as bond pairs or shared pairs.

4.52.  (i) Linear

(ii) Tetrahedral