NCERT Class11 Chemistry Molecular Structure,Bond angle,bond order

Chemical Bonding Molecular Structure Mock Test-1

Which of the following statements regarding chemical bond is incorrect?

(a) The attractive force that holds various constituents together in different species is called a chemical bond.
(b) Lewis postulated that atoms achieve the stable octet when they are linked by chemical bonds.
(c) The bond formed as a result of the electrostatic attraction between two positively ions is termed as t lie electrovalent bond
(d) When two atoms share one electron pair they are said to be joined by a single covalent bond

What is the electrovalency and charge of calcium and chlorine respectively?

(a) Positive electrovalence of two and negative electrovalence of one.
(b) Negative electrovalence of one and positive electrovalence of two.
(c) Positive electrovalence of one and negative electrovalence of two.
(d) Negative electrovalence of two and positive electrovalence of one.

Select the correct statement regarding octet rule.

(a) Atoms can combine by transfer of valence electrons from one atom to another, gaining or losing.
(b) Atom can combine by sharing of valence electrons in order to have an octet in their valence shells.
(c) both (a) and (b) are correct.
(d) Neither (a) nor (b) are correct.

Which of the following species does not possess triple bond?

(a) C2H2
(b) N2
(c) CCl4
(d) HCN


In CH4 molecule, how many valence electrons are available for bonding?

(a) Eight
(b) Four
c) Six
(d) Ten

Select the correct statement

(a) In NF3, and CO32-, nitrogen and fluorine are the central atoms whereas carbon and oxygen occupy the terminal positions.
(b) In NF3, and CO32-, nitrogen and carbon are the central atoms whereas fluorine and oxygen occupy the terminal positions.
(c) In NF3, and CO32-, fluorine and oxygen are the central atoms whereas nitrogen and carbon occupy the terminal positions.
(d) In NF3, and CO32-, nitrogen and oxygen are the central atoms whereas fluorine and carbon occupy the terminal positions.

Central oxygen atom in ozone (O3) consists of formal charge equal to

(a) -1
(b) 0
c) +1
(d) None of these

How many lone pairs of electrons are available in ozone molecule?

(a) Eight
b) Four
(c) Two
d) Six

Some statements regarding formal charge are given below. Identity the correct statements.
(i) Formal charges do not Indicate real charge separation within the molecule.
(ii) Formal charges help in the selection of the lowest energy structure from a number of possible Lewis structures for a given species.
(iii) In polyatomic ions. It is feasible to assign a formal charge on each atom,

(a) I only
(b) II and III
(c) I and III
(d) I. II and III

Which of the following is an example of odd electron molecule?

(a) BCl3
(b) NO
(c) CO
(d) H2O

Identify the molecule which has incomplete octet of the central atom.

(a) BeH2
(b) C2H2
(c) NF3
(d) CO2

Question:-No: 13
Which of the following pairs of molecules has expanded octet?

(a) SF6, H2O
(b) H2SO4LiCl
(c) PF5 and SF6
(d) CO2 and PF5

Match Column I with Column II and select the correct code given below:
Column I— Column II
Molecule –Octet rule
(P) BCl3 (1) Expanded octet
(Q) H2SO4 (2) Odd electron
(R) NO2 (3) Incomplete octet
(S) NF3 (4) Complete octet

(a) P- 1,Q -2 ,R – 3,S – 4
(b)P- 4,Q- 3, R- 2,S – 1
(c) P – 3, Q-1, R- 4, S- 2
(d) P – 3, Q -1, R- 2, S – 4

Which of the following molecules follows the octet rule?

(a) SCl2
(b) SF6
(c) NO2
(d) LiCl

Question:-No: 16
Some statements regarding octet theory are given below. Identify the correct statement(s).
(I) This theory does not account for the shape of molecules.
(II) It does not explain the relative stability of the molecules.
(Ill) This theory is totally silent about the energy of a molecule.

(a) II only
(b) I and III
(c) II and III
(d) I. II and III