JEE Chemistry Chemical Bonding and Molecular Structure MCQs Set A

Question: The attractive force which holds various constituents (atoms, ions etc.) together in different chemical species is called a

• a) chemical bond
• b) ionic bond
• c) chemical compound
• d) covalent bond

Answer: chemical bond

Question: The evolution of various theories of valence and the interpretation of the nature of chemical bonds have closely been related to the developments in the understanding of

• a) All of the above
• b) periodic table
• c) electronic configuration of elements
• d) structure of atom

Answer: All of the above

Question: Who provide explanation of valence based on intertness of noble gases ?

• a)

  

• b)

  

• c) Lewis
• d) Langmuir

Answer:

Question: In the formation of a molecule which of the following take part in chemical combination?

• a) valence electron
• b) cation
• c) anion
• d) inner shell electron

Answer: valence electron

Question:

• a) II & III
• b) II, III & IV
• c) I, IV & V
• d) II only

Answer: II & III

Question: The bond formed as a result of the electrostatic attraction between the positive and negative ions is termed as

• a) Electrovalent bond
• b) Covalent bond
• c) Chemical bond
• d) Co-ordinate bond

Answer: Electrovalent bond

Question: Cation and anion combines in a crystal to form following type of compound

• a) ionic
• b) metallic
• c) dipole-dipole
• d) covalent

Answer: ionic

Question: Electrovalence of calcium and chlorine respectively is

• a) + 2, – 1
• b) + 1, – 2
• c) + 1, – 1
• d) + 2, – 2

Answer: + 2, – 1

Question: When a metal atom combines with non-metal atom, the non-metal atom will

• a) gain electrons and increase in size
• b) lose electrons and increase in size
• c) lose electrons and decrease in size
• d) None of these

Answer: gain electrons and increase in size

Question: Who introduced the term covalent bond ?

• a) Langmuir
• b) Heitler and London
• c) Lewis
• d) Nyholm and Gillespie

Answer: Langmuir

Question: Which of the following is/are not the condition(s) for Lewis dot structure?

(i) Each bond is formed as a result of sharing of an electron pair between the atoms.
(ii) From the two combining atoms only one atom contribute electron(s) to the shared pair.
(iii) The combining atoms attain the outer shell noble gas configurations as a result of the sharing of electrons.

• a) (ii) only
• b) (i) and (iii)
• c) (ii) and (iii)
• d) (iii) only

Answer: (ii) only

Question: Which of the following does not represent the correct Lewis dot structure?

• a) A
• b) C
• c) B
• d) A and C

Answer: A

Question: Which of the following statements are correct based on given Lewis dot structure ?

• a) (i) and (iv) represents formation of triple bond
• b) Only (iii) represents formation of double bond
• c) Only (ii) represents formation of single bond
• d) (ii) and (iii) both represents formation of single bond

Answer: (i) and (iv) represents formation of triple bond

Question:

• a) Only I
• b) Only III
• c) Only II
• d) I, II and III

Answer: Only I

Question: In N₂ molecule, the number of electrons shared by each nitrogen atom is

• a) 3
• b) 1
• c) 2
• d) 5

Answer:  3

Question: Which of the following represents the Lewis structure of N₂ molecule?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Which of the following shows the Lewis dot formula for CO₂ ?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Which of the following is the correct electron dot structure of N₂O molecule?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) 

  X = Total number of valence electrons in the free atom
  Y = Total number of non bonding electrons
  Z = Total number of bonding electrons

• b) None of these
• c)

  X = Total number of electrons in the free atom
  Y = Total number of non bonding electrons
  Z = Total number of valence electrons

• d)

  X = Total number of non bonding electrons
  Y = Total number of bonding electrons
  Z = Total number of valence electrons in the free atom

Answer:

X = Total number of valence electrons in the free atom
Y = Total number of non bonding electrons
Z = Total number of bonding electrons

Question: The lowest energy structure is the one with the _____ formal charges on the atoms.

• a) smallest
• b) highest
• c) negative
• d) zero

Answer: smallest

Question:

• a) – 0.75, 1.25
• b) –0.75, 0.6
• c) – 0.75, 1.0
• d) –3, 1.25

Answer: – 0.75, 1.25

Question: In the cyanide ion, the formal negative charge is on

• a) N
• b) C
• c) Resonate between
• d) All of these

Answer: N

Question: What are the exceptions of the octet rule ?

• a) All of these
• b) Expanded octet of the central atom
• c) An odd number of electrons on central atom
• d) The incomplete octet of central atom

Answer: All of these

Question: In which of the following molecules octet rule is not followed?

• a) NO
• b) CH₄
• c) NH₃
• d) CO₂

Answer: NO

Question:

• a) (i), (ii), (iii)
• b) (ii), (iii), (iv)
• c) (i), (ii), (iii), (iv)
• d) (i), (iii), (iv)

Answer: (i), (ii), (iii)

Question: Among the following the electron deficient compound is

• a) BCl₃
• b) CCl₄
• c) BeCl₂
• d) PCl₅

Answer: BCl₃

Question: Which of the following is the electron deficient molecule?

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: Which of the following compounds does not follow the octet rule for electron distribution?

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question:

• a) NO and ClO₂
• b) CO and SO₂
• c) SO₂ and O₃
• d) None of these

Answer: NO and ClO₂

Question: Complete the following statement by choosing theappropriate option. Ionic bonds will be formed more easily between elements with comparatively A and elements with comparatively high negative value of B .

• a) 

  A = low ionization enthalpy
  B = electron gain enthalpy

• b)

  A = high ionization enthalpy
  B = electron gain enthalpy

• c)

  A = low electronegativity
  B = ionization enthalpy

• d)

  A = high electronegativity
  B = ionization enthalpy

Answer:

A = low ionization enthalpy
B = electron gain enthalpy

Question: In ionic solids how crystal structure get stabilized

• a) By the energy released in the formation of crystal lattice
• b) By achieving octet of electrons around the ionic species in gaseous state
• c) By electron gain enthalpy and the ionization enthalpy
• d) None of these

Answer: By the energy released in the formation of crystal lattice

Question: Energy required to completely separate one mole of a solid ionic compound into gaseous constituent ions is called

• a) Lattice enthalpy
• b) Bond dissociation enthalpy
• c) Electron gain enthalpy
• d) Ionisation enthalpy

Answer: Lattice enthalpy

Question: The effect of more electronegative atom on the strength of ionic bond

• a) increases
• b) decreases
• c) decreases slowly
• d) remains the same

Answer: increases

Question: Which of the following combination will form an electrovalent bond ?

• a) H and Ca
• b) P and Cl
• c)

  

• d) H and S

Answer: H and Ca

Question: Among the following which compound will show the highest lattice energy ?

• a) NaF
• b) RbF
• c) RbF
• d) KF

Answer: NaF

Question: Which of the following bond will have highest ionic character?

• a) H–F
• b) H–Br
• c) H–I
• d) H–Cl

Answer: H–F

Question: Which of the following pairs will form the most stable ionic bond ?

• a) Mg and F
• b) Na and F
• c) Na and Cl
• d) Li and F

Answer: Mg and F

Question: Which of the following methods is used for measuring bond length ?

• a) All of these
• b) Spectroscopic techniques
• c) Electron-diffraction
• d) X-ray diffraction

Answer: All of these

Question: _______ is measured as the radius of an atom’s core which is in contact with the core of an adjacent atom in a bonded situation

• a) Covalent radius
• b) Ionic radius
• c) Bond length
• d) van der Waal’s radius

Answer: Covalent radius

Question:  Following figure represent a chlorine molecule. Identify A B and C in the given figure

• a)

  A = Covalent radius, B = van der Waal’s radius
  C = Bond length

• b)

  A = Ionic radius, B = van der Waal’s radius
  C = Covalent radius

• c)

  A = Covalent radius, B = Bond length
  C = Ionic radius

• d)

  A = Bond length, B = van der Waal’s radius
  C = Covalent radius

Answer:

A = Covalent radius, B = van der Waal’s radius
C = Bond length

Question: Which of the following statement is correct?

• a) All of these
• b) Larger the bond dissociation enthalpy, stronger will be the bond in the molecule
• c) The unit of bond enthalpy is kJ mol^–1
• d) Amount of energy required to break one mole of bonds of a particular type between two atoms in a gaseous state is called bond enthalpy.

Answer: All of these

Question:

• a) Both
• b) I, II and IV have same bond order
• c) III and V have same bond order
• d) None of the above

Answer: Both

Question: Which one of the following is not correct representation of resonance ?

• a) Both A and B
• b) Only A
• c) Only B
• d) None of the above

Answer: Both A and B

Question: Which of the following structure represents structure of O₃ more accurately?

• a) III
• b) I
• c) II
• d) I and II

Answer: III

Question: Which of the following is/are misconception(s) associated with resonance ?

(i) The molecule exist for a certain fraction of time in one cannonical form and for other fractions of time in other cannonical forms.
(ii) The cannonical forms have no real existence.
(iii) There is no such equilibrium between the cannonical forms.

• a) (i) only
• b) (i) and (iii)
• c) (ii) and (iii)
• d) (iii) only

Answer: (i) only

Question: 

• a) 3
• b) 9
• c) 2
• d) 6

Answer: 3

Question: Which one of the following is not the resonance structure of CO₂?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: All the bond lengths of sulphur – oxygen in sulphate ion, are equal because of

• a) resonance
• b) symmetry
• c) high electronegativity of oxygen
• d) None of these

Answer: resonance

Question: Resonance is due to

• a) delocalization of pi electrons
• b) delocalization of sigma electrons
• c) migration of protons
• d) None of these

Answer: delocalization of pi electrons

Question: Which one of the following pairs of molecules will have permanent dipole moments for both members ?

• a) 

  

• b)

  

• c)

  

• d)

  

Answer:

Question: The molecule which has zero dipole moment is

• a) BF₃
• b) NF₃
• c) ClO₂
• d) None of these

Answer: BF₃

Question: Which of the following has dipole moment?

• a) NH₃
• b) CO₂
• c) CH₄
• d) None of these

Answer:  NH₃

Question: Identify the non polar molecule in the following compounds

• a) H₂
• b) HCl
• c) HBr
• d) HF and HBr

Answer: H₂

Question: A neutral molecule XF₃ has a zero dipole moment. The element X is most likely

• a) boron
• b) carbon
• c) chlorine
• d) nitrogen

Answer: boron

Question:  Among the following, the molecule of high dipole moment is

• a) H₂O
• b) CCl₄
• c)  NH₃
• d) CHCl₃

Answer: H₂O

Question: Which one of the following molecules is expected to have zero dipole moment?

• a) CO₂
• b) CaF₂
• c) H₂O
• d) SO₂

Answer: CO₂

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: The most polar bond is

• a) C – F
• b) C – Br
• c) C – O
• d) C – S

Answer: C – F

Question:

• a) b, c and d
• b) b and c
• c) a and c
• d) a and b

Answer: b, c and d

Question: According to Fajan’s rule, covalent bond is favoured by

• a) Small cation and large anion
• b) Small cation and small anion
• c) Large cation and large anion
• d) Large cation and small anion

Answer: Small cation and large anion

Question:

• a) (ii), (i), (iii), (iv)
• b) (i), (ii), (iii), (iv)
• c) (iv), (ii), (i), (iii)
• d) (iii), (i), (ii), (iv)

Answer: (ii), (i), (iii), (iv)

Question: The correct sequence of increasing covalent character is represented by

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: Which of the following salt shows maximum covalent character?

• a) AlCl₃
• b) None of these
• c) MgCl₂
• d) LaCl₃

Answer: AlCl₃

Question:  Polarisibility of halide ions increases in the order

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: The covalent bond length is the shortest in which one of the following bonds?

• a) O — H
• b) C — C
• c) C — O
• d) None of these

Answer:  O — H

Question: Hydrogen chloride molecule contains

• a) polar covalent bond
• b) co-ordinate bond
• c) double bond
• d) electrovalent bond

Answer: polar covalent bond

Question: Sodium chloride is an ionic compound whereas hydrogen chloride is mainly covalent because

• a) hydrogen is non-metal
• b) hydrogen chloride is a gas
• c) sodium is less reactive
• d) electronegativity difference in the case of hydrogen and chlorine is less than 2.1

Answer: hydrogen is non-metal

Question: According to VSEPR theory the geometry of a covalent molecules depends upon

• a) All the above
• b) the number of electron pairs present in the outer shell of the central atom
• c) the number of lone pairs of electrons
• d) the number of bond pairs of electrons

Answer: All the above

Question:

• a) pyramidal
• b) square planar
• c) tetrahedral
• d) planar triangular

Answer: pyramidal

Question: In BrF₃ molecule, the lone pairs occupy equatorial positions to minimize

• a) lone pair - lone pair repulsion and lone pair - bond pair repulsion
• b) lone pair - lone pair repulsion only
• c) bond pair - bond pair repulsion only
• d) lone pair - bond pair repulsion only

Answer: lone pair - lone pair repulsion and lone pair - bond pair repulsion

Question:  Which of the correct increasing order of lone pair of electrons on the central atom?

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: The number of lone pair and bond pair of electrons on the sulphur atom in sulphur dioxide molecule are respectively

• a) 1 and 4
• b) 4 and 1
• c) 1 and 3
• d) 3 and 1

Answer: 1 and 4

Question: A molecule has two lone pairs and two bond pairs around the central atom. The molecule shape is expected to be

• a) V-shaped
• b) linear
• c) triangular
• d) tetrahedral

Answer:  V-shaped

Question: Using VSEPR theory, predict the species which has square pyramidal shape

• a) BrF₅
• b) CCl₄
• c) SnCl₂
• d) SO₃

Answer: BrF₅

Question: Among the following molecules : SO₂, SF₄, CIF₃, BrF₅ and XeF₄, which of the following shapes does not describe any of the molecules mentioned?

• a) Trigonal bipyramidal
• b) T-shape
• c) Bent
• d) See-saw

Answer: Trigonal bipyramidal

Question:

• a) Only I
• b) Only II
• c) Only III
• d) All three have same stability

Answer: Only I

Question:

• a) 2
• b) 0
• c) 1
• d) can be predicted only if atomic number of M is known

Answer: 2

Question: Shape of methane molecule is

• a) tetrahedral
• b) pyramidal
• c) square planar
• d) octahedral

Answer: tetrahedral

Question: The shape of stannous chloride molecule is

• a) bent
• b) square planar
• c) see-saw
• d) trigonal pyramidal

Answer: bent

Question: Look at the following potential energy curve which of the following correctly represents the most stable state of hydrogen molecule.

• a) B
• b) D
• c) A
• d) C

Answer: B

Question: Which of the following statements is false ?

• a) Acetylene molecule has three pi bonds and three sigma bonds
• b) Water molecule has two sigma bonds and two lone pairs
• c) HCl molecule has one sigma bond
• d) None of these

Answer: Acetylene molecule has three pi bonds and three sigma bonds

Question:

• a) 17 and 4
• b) 15 and 4
• c) 16 and 5
• d) 14 and 3

Answer: 17 and 4

Question: Allyl cyanide molecule contains

• a) 9 sigma bonds, 3 pi bonds and one lone pair
• b) 9 sigma bonds, 4 pi bonds and no lone pair
• c) 8 sigma bonds, 5 pi bonds and one lone pair
• d) 8 sigma bonds, 3 pi bonds and two lone pairs

Answer: 9 sigma bonds, 3 pi bonds and one lone pair

Question:

• a) Cl₂
• b) N₂
• c) O₂
• d) CO₂

Answer: Cl₂

Question:

• a) 5, 4 and 6
• b) 5, 3 and 6
• c) 6, 3 and 5
• d) 6, 4 and 5

Answer: 5, 4 and 6

Question: The enolic form of a acetone contains

• a) 9 sigma bonds, 1 pi bond and 2 lone pairs
• b) 8 sigma bonds, 2 pi bonds and 2 lone pairs
• c) 10 sigma bonds, 1 pi bond and 1 lone pair
• d) 9 sigma bonds, 2 pi bonds and 1 lone pair

Answer: 9 sigma bonds, 1 pi bond and 2 lone pairs

Question: The angle between the overlapping of one s-orbital and one p-orbital is

• a) 180°
• b) 120°
• c) 120° 60'
• d) None of these

Answer: 180°

Question: Linear combination of two hybridized orbitals belonging to two atoms and each having one electron leads to a

• a) sigma bond
• b) double bond
• c) co-ordinate covalent bond
• d) pi bond

Answer: sigma bond

Question:  Which of the following statements is not correct ?

• a)

  

• b) Double bond is stronger than a single bond
• c) Covalent bond is stronger than hydrogen bond
• d) Double bond is shorter than a single bond

Answer:

Question: Which of the following represents zero overlap of atomic orbitals.

• a)

  

• b)

  

• c)

  

• d) All of these

Answer:

Question: Which of the following is/are not essential condition(s) for hybridisation?

(i) The orbitals present in the valence shell of the atom are hybridised.
(ii) The orbitals undergoing hybridisation should have almost equal energy.
(iii) Promotion of electron is essential prior to hybridisation.
(iv) Only half filled orbitals participate in hybridisation.

• a) (iii) and (iv)
• b) (iii) only
• c) (i) only
• d) (iv) only

Answer: (iii) and (iv)

Question: As the s-character of hybridised orbital increases, the bond angle

• a) increase
• b) becomes zero
• c) does not change
• d) decrease

Answer: increase

Question:  The nature of hybridisation in the ammonia molecule is

• a) sp³
• b) dp²
• c) sp²
• d) sp

Answer: sp³

Question: The shape of sulphate ion is

• a) tetrahedral
• b) triagonal
• c) square planar
• d) trigonal planar

Answer: tetrahedral

Question: The strength of bonds formed by s–s and p–p, s–p overlap in the order of

• a) s–s > s–p > p–p
• b) p–p > s–s > s–p
• c) s–p > s–s > p–p
• d) s–s > p–p > s–p

Answer:  s–s > s–p > p–p

Question:

• a) XeF₆
• b) BrF₅
• c) PCl₅
• d) SF₆

Answer: XeF₆

Question: The shape of CO₂ molecule is

• a) linear
• b) planar
• c) pyramidal
• d) tetrahedral

Answer: linear