One or more types of elements make up matter. Except for noble gases, no other element can be found in nature as an independent atom under normal circumstances. However, it has been discovered that a collection of atoms exists as a single species with distinct characteristics. A molecule is a name given to such an assembly of atoms. Obviously, there must be a force holding these individual atoms of the molecules together. A chemical bond is a binding force that binds various constituents (atoms, ions, etc.) in various chemical species.
CBSE Class 11 Chemistry Chapter 4 Chemical Bonding and Molecular Structure – Set 1
Q-1: Which of the following carbon is more electronegative?
a) sp hybridised carbon
b) sp3 hybridised carbon
c) sp2 hybridised carbon
d) Always the same irrespective of the hybrid state
Q-2: In the ClF3 molecule, the lone pairs occupy an equatorial position to minimise
a) Bond pair – bond pair repulsion only
b) Lone pair – bond pair repulsion only
c) Lone pair – lone pair repulsion and lone pair – bond pair repulsion
d) Lone pair – lone pair repulsion only
Q-3: Which of the following statements is false?
a) The double of the distance between two similar atoms connected by a covalent bond is the covalent radius.
b) In a solid, the van der Waals radius is equal to half of the distance between two comparable atoms in different molecules.
c) Spectroscopic, X-ray, and electron diffraction methods are used to measure bond lengths.
d) None of the above
Q-4: A 𝜋- bond is formed by the overlap of
a) p-p orbitals
b) s-s orbitals
c) p-p orbitals in an end-to-end manner
d) p-p orbitals in a sidewise manner
Q-5: Which of the following accurately describes the prerequisites for the formation of an electrovalent bond?
a) Low ionisation potential of one atom and high electron affinity of the other atom.
b) Both atom’s high ionisation potential and electron affinity.
c) Both atom’s low ionisation potential and low electron affinity.
d) One atom with a high ionisation potential and another with a high affinity for electrons.
Q-6: What is the valence bond approach for forming a covalent bond and a coordinate bond?
Q-7: Write Lewis dot symbols for the following ions:
i) O2-
ii) Mg2+
iii) N3-
Q-8: What information did Kossel provide about chemical bonding?
Q-9: State with reasons
a) Which is more acidic – anhydrous HCl or aqueous HCl?
b) Which is more polar – CO2 or N2O?
Q-10: AlCl3 is covalent when anhydrous. Determine whether it would remain covalent or change to an ionic state in an aqueous solution using the information provided below. Ionisation energy for AlCl3 = 5137 kJ/mol, ΔHhydration for Al3+ = -4665 kJ/mol, ΔHhydration for Cl– = -381 kJ/mol.
Q-11: Draw the molecular structures of OsF4 and XeF4 using the VSEPR theory, highlighting the location of lone pairs of electrons and the hybridisation of the central atom.
Q-12: Determine the HCl’s ionic character percentage. Given that the HCl’s bond length is 1.275 and the observed dipole moment is 1.83 D.
Q-13: Describe the change in hybridisation, if any,
a) Of Al atom in the reaction AlCl3 + Cl– → AlCl4–?
b) Of B and N atoms in the reaction BF3 + NH3 → F3B-NH3?
Q-14: Describe how Lewis’ concept differs from VB theory.
Q-15: Out of sp-hybrid orbital and p orbital, which has greater directional character and why?
Q-16: When we state that the lattice energy of NaCl is 788 kJ/mol. What does it mean?
Q-17: Calculate the formal charge of S in the following structure.
Q-18: Give two resonating structures of ozone which satisfy the octet rule. Also, give the probable hybrid structure.
Q-19:
i) Why does MgCl2 have a much higher solubility than MgF2?
ii) Why is the melting point of MgO (2800OC) much higher than that of BaO (1920OC)?
Q-20: How will you differentiate between the lone pair and a bond pair of electrons?
Download the PDF to access answers to the Chemistry Worksheet for Class 11 Chemistry Chapter 4 Chemical Bonding and Molecular Structure Set – 1.
