Chemical Bonding and Molecular Structure - Online Test

Q1. The maximum number of hydrogen bonds that a molecule of water can have is
Answer : Option B
Explaination / Solution:


The two hydrogens of the water molecule can form hydrogen bonds with other oxygens in water, and the two lone pair of electrons on oxygen of the water molecule can attract other hydrogens in water. Hence, 4 possible hydrogen bonds.


Q2. During the formation of a chemical bond
Answer : Option C
Explaination / Solution:

A chemical bond is a lasting attraction between atoms that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between atoms with opposite charges, or through the sharing of electrons as in the covalent bonds. When a bond forms, electrons are attracted to the space between nuclei where the electrostatic force of attraction is greater. As the electrons fall to a position of lower potential energy, the total mechanical energy of the molecular system decreases. Part of the mechanical energy of the unbound atoms is lost when they form the molecular system with a lower total mechanical energy. Lower the energy higher the stability of bond.

Q3. Which of the following has maximum number of lone pairs associated with Xe?
Answer : Option D
Explaination / Solution:

  • n XeF​​​​2Xe has 2 of its electrons in bonding with F. So, since Xe has 8 valence electrons,  the no.of lone pairs = 
  • In XeO3: Xe has 6 of its electrons in bonding with O (bcoz of double bond). So, Xe will have 2 non bonding electrons and therefore 1 lone pair.
  • In XeF4: Xe has 4 of its electrons in bonding with F. So, Xe will have 4 non bonding electrons and therefore 2 lone pairs.
  • In XeF6: Xe has 6 of its electrons in bonding with F. So, Xe will have 2 non bonding electrons and therefore 1 lone pair.

So XeF2 has the maximum no. of lone pairs associated with Xe.


Q4. The structure of  is
Answer : Option C
Explaination / Solution:


In IF7 out of 7 Flourine atoms 5 of them are placed on a plane in Pentagon shape. In remaining 2 flourines one is placed above the plane and other below the plane each at 90 degrees


Q5. The number of types of bonds between two carbon atoms in calcium carbide is
Answer : Option C
Explaination / Solution:


CaC2 has a combination of bonds. It is an ionic lattice that has Ca2+ cations and acetylide C22- anions. Within each C22-there is a triple bond between the 2C atoms, consisting of 1 sigma and 2 pi bonds.


Q6. The hybridization of orbitals of N atom in and are respectively
Answer : Option C
Explaination / Solution:

Hybridization of orbitals of N atom in and are 
Q7. Among the following the maximum covalent character is shown by the compound
Answer : Option A
Explaination / Solution:

Few ionic bonds have partial covalent characteristics which were first discussed by a scientist, Kazimierz Fajans in 1923. He gave the rule to predict whether a chemical bond will be covalent or ionic which is now commonly known as Fajan’s rule. The rule can be stated as:

  • Size of the ion: Smaller the size of cation, larger the size of anion, greater is the covalent character of the ionic bond.
  • Charge of Cation: Greater the charge of cation, greater is the covalent character of the ionic bond.
  • Electronic configuration- For cations with same charge and size, the one, with (n-1)dnns​​​0 which is found in transition elements have greater covalent character than the cation with ns2np6 electronic configuration, which is commonly found in alkali or alkaline earth metals.

Keeping these rules in mind, we can say that AlCl​​​3 has high covalent character.


Q8. Which one of the following is paramagnetic?
Answer : Option C
Explaination / Solution:

The number of electrons in Nitrogen are 7 and in oxygen are 8. Hence the number of electrons that would be present in the molecular orbitals in NO are 7 + 8 = 15. As the number of electrons are odd, all the electrons in NO molecule cannot be paired. Hence, a single electron would be present in a π*2p orbital. Therefore NO is an odd electron species and the gas is hence paramagnetic due to the presence of unpaired electron.

Q9. Hybridization of and of are
Answer : Option A
Explaination / Solution:

C2 is sp2 while C3 is sp (special case of allenes)

Q10. The  hybridization of central atom of a molecule would lead to
Answer : Option D
Explaination / Solution:

In sp3d2 Hybridization one s, three p and two d-orbitals get hybridized to form six sp3d2 hybrid orbitals which adopt octahedral arrangement as given in image below