Free NCERT Solutions For Class 11 Chemistry Chapter 4 : Chemical Bonding and Molecular Structure Free PDF Download

Question 1:
Explain the formation of a chemical bond.

Question 2:
Write Lewis dot symbols for atoms of the following elements: Mg, Na, B, O, N, Br.

Question 3:
Write Lewis symbols for the following atoms and ions:
S and S2-; Al and Al3+; H and H-

Question 4:
Draw the Lewis structure for the following molecules and ions:
H2S, SiCl4, BeF2, 2- CO3, HCOOH.

Solution4:

Question 5:
Define octet rule. Write its significance and limitations.

Question 6:
Write the favourable factors for the formation of ionic bond.

Question 7:
Discuss the shape of the following molecules using the VSEPR model:
BeCl2, BCl3, SiCl4, AsF5, H2S, PH3.

Question 8:
Although geometries of NH3 and H2O molecules are distorted tetrahedral, bond angle in water
is less than that of ammonia. Discuss.

Question 9:
How do you express the bond strength in terms of bond order?

Question 10:
Define the bond length.

Question 11:
Explain the important aspects of resonance with reference to the 2- CO3 ion.

Question 12:
H3PO3 can be represented by structures 1 and 2 shown below. Can these two structures be
taken as the canonical forms of the resonance hybrid representing H3PO3? If no, give reason
for the same.

Question 13:
Write the resonance structures for SO3, NO2 and NO3.

Question 14:
Use Lewis symbols to show electron transfer between the following atoms to form cations and
anions: (a) K and S (b) Ca and O (c) Al and N.

Question 15:
Although both CO2 and H2O are triatomic molecules, the shape of H2O molecule is bent while
that of CO2 is linear. Explain this on the basis of dipole moment.

Question 16:
Write the significance/applications of dipole moment.

Question 17:
Define electronegativity. How does it differ from electron gain enthalpy?

Question 18:
Explain with the help of suitable example polar covalent bond.

Question 19:
Arrange the bonds in order of increasing ionic character in the molecules: LiF, K2O, N2, SO2,
and ClF3.

Question 20:
The skeletal structure of CH3COOH as shown below is correct, but some of the bonds are
shown incorrectly. Write the correct Lewis structure for acetic acid.

Question 21:
Apart from tetrahedral geometry, another possible geometry for CH4 is square planar with the
four H atoms at the corners of the square and the C atom at its centre. Explain why CH4 is not
square planar?

Question 22:
Explain why BeH2 molecule has a zero dipole moment although the Be-H bonds are polar.

Question 23:
Which out of NH3 and NF3 has higher dipole moment and why?

Question 24:
What is meant by hybridization of atomic orbitals? Describe the shapes of sp, sp2 , sp3 hybrid orbitals.

Question 25:
Describe the change in hybridization (if any) of the Al atom in the following reaction.

Question 26:
Is there any change in the hybridization of B and N atoms as a result of the following reaction?

Question 27:
Draw diagrams showing the formation of a double bond and a triple bond between carbon
atoms in C2H4 and C2H2 molecules.

Question 28:
What is the total number of sigma and pi bonds in the following molecules?
(a) C2H2 (b) C2H4

Question 29:
Considering x-axis as the inter-nuclear which out of the following will not form a sigma bond
and why? (a) 1s and 1s (b) 1s and 2px (c) 2py and 2py (d) 1s and 2s.

Question 30:
Which hybrid orbitals are used by carbon atoms in the following molecules?
(a) CH3 – CH3 ; (b) CH3 – CH = CH2; (c) CH3 – CH2 – OH; (d) CH3-CHO (e) CH3COOH.

Question 31:
What do you understand by bond pairs and lone pairs of electrons? Illustrate by giving one
example of each type.

Question 32:
Distinguish between a sigma and a pi bond.

Question 33:
Explain the formation of H2 molecule on the basis of valence bond theory.

Question 34:
Write the important conditions required for the linear combination of atomic orbitals to form
molecular orbitals.

Question 35:
Use molecular orbital theory to explain why the Be2 molecule does not exist.

Question 36:
Compare the relative stability of the following species and indicate their magnetic properties;

Question 37:
Write the significance of a plus and a minus sign shown in representing the orbitals.

Question 38:
Describe the hybridization in case of PCl5. Why are the axial bonds longer as compared to
equatorial bonds?

Question 39:
Define hydrogen bonds. Is it weaker or stronger than the van der Waals forces?

Question 40:
What is meant by the term bond order? Calculate the bond order of: N2, O2,O2+, O2-.