Test: Chemical Bonding- 3 - Chemistry MCQ

In B the central atoms are S and I+ respectively, having 6 e- each and the others are from G-VII. Hence, they will have the same lone pair repulsion.

Hence B is correct.

Electronegativity decreases down the group, the electron density also decreases and consequently the repulsive interactions between the electron pairs also decrease thereby decreasing the bond angle H-M-H

a) NH₃ ammonia has bond angle = 107.8 deg.
Bond angle of Ph₃ = 93 deg.

NH₃ > PH₃ (True)

b) The bond angle of H₂O is 105 deg
The bond angle of H₂S is 90 deg

H₂S < H₂O (True)

c) bond angle of NO₂⁺ is 180 deg
bond angle of NO₂ is 134.4 deg

NO₂⁺ > NO₂ (True)

d)  bond angle of NO₂⁺ is 180 deg

 bond angle of NO₂^- is 115 deg

NO₂⁺ > NO₂^– (True)

Correct Answer :- c

Explanation : The bond polarity is directly proportional to the electronegativity of the atom.

As we move down the group, radius of elements increases and electronegativity decreases so bond angle decreases.

So, bond polarity will be : H₂O < NH₃< H₂S < PH₃

Paramagnetism is due to the presence of at least one unpaired electron in the molecule. Though NO₂ is paramagnetic, its dimer, N₂O₄, is diamagnetic. The two unpaired electrons in the two NO₂ units get paired while forming the dimer, and so N₂O₄ is diamagnetic with even number of electrons.

Due to larger atomic size P is unable to form pi bond and so it is tetra-atomic in which each P atom is linked with 3 other P atoms by 3 sigma bonds. 

But, due to smaller atomic size N forms 1 sigma and 2 pi bonds i.e. triple bonds with other N atom and exists as diatomic molecules. Hence the bonding is responsible for that.

 Phosporous form  P₄​ because in  P₂​  pπ-pπ bond is weaker.

Boron trifluoride is planar and the bond angle is 120 degrees. This can be predicted from VSEPR theory. There are three bonding pairs of electrons and no lone pairs on the central atom

Bond angle 96.2∘.

Here, the AsBr₃ has the greatest and the AsF₃ has the shortest bond angles among the three due to variance in size and electronegativity.

PH₅ and NI₃ doesnt exist.

In O₂F₂, one O - O bond and two O - F bonds are lying in different planes, i.e. this molecule like H₂O₂ has non-linear and non-planar structure.