JEE Chemistry Chemical Bonding and Molecular Structure MCQs Set B

Question: The hybridisation state of carbon in fullerene is

• a) sp²
• b) sp³d
• c) sp
• d) sp³

Answer: sp²

Question: Which of the following statements is true for an ion having sp³ hybridisation?

• a) H-atoms are situated at the corners of tetrahedron
• b) all bonds are co-ordinate covalent
• c) H-bonds are situated at the corners of a square
• d) all bonds are ionic

Answer: H-atoms are situated at the corners of tetrahedron

Question: Which of the following molecule does not have a linear arrangement of atoms ?

• a) H₂S
• b) CO₂
• c) BeH₂
• d) All of these

Answer: H₂S

Question: In which one of the following molecules the central atom said to adopt sp² hybridization?

• a) BF₃
• b) NH₃
• c) BeF₂
• d) None of these

Answer: BF₃

Question: Considering the state of hybridization of carbon atoms, find out the molecule among the following which is linear ?

• a)

  

• b)

  

• c)

  

• d) All of these

Answer:

Question: Equilateral shape has

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: In an octahedral structure, the pair of d orbitals involved in d²sp³ hybridization is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: In which of the following species is the underlined carbon having sp³ - hybridisation ?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: A sp³-hybrid orbital contains

• a) 25% s-character
• b) 50% s-character
• c) 75% s-character
• d) 25% p-character

Answer: 25% s-character

Question: The types of hybridisation of the five carbon atoms from left to right in the molecule

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question:  Pick out the incorrect statement from the following

• a) sp³d² hybrid orbitals are equivalent and are oriented towards corners of a regular octahedron
• b) sp³d³ hybrid orbitals are not equivalent
• c) sp hybrid orbitals are equivalent and are at an angle of 180° with each other
• d) sp² hybrid orbitals are equivalent and bond angle between any two of them is 120°

Answer: sp³d² hybrid orbitals are equivalent and are oriented towards corners of a regular octahedron

Question: All carbon atoms are sp² hybridised in

• a) 1, 3-butadiene
• b) cyclohexane
• c) CH₂ = C = CH₂
• d) 2-butene

Answer: 1, 3-butadiene

More Questions..........................................

Question: Which one of the following is not correct in respect of hybridization of orbitals?

• a) Pure atomic orbitals are more effective in forming stable bonds than hybrid orbitals
• b) The orbitals undergoing hybridization have almost equal energy
• c) Promotion of electron is not essential condition for hybridization
• d) The orbitals present in the valence shell only are hybridized

Answer: Pure atomic orbitals are more effective in forming stable bonds than hybrid orbitals

Question: Molecular orbital theory was given by

• a) Mulliken
• b) Kossel
• c) Mosley
• d) Werner

Answer: Mulliken

Question:  Atomic orbital is monocentric while a molecular orbital is polycentric. What is the meaning of above statements?

• a) While an electron in an atomic orbital is influenced by one nucleus, in a molecular orbital it is influenced by two or more nuclei depending upon the number of atoms in the molecule
• b) Electron density in atomic orbital is given by the electron distribution around a nucleus in an atom. While in molecular orbital it is given by the electron distribution around group of nuclei in a molecule.
• c) The electron in an atomic orbital is present in one nucleus while in molecular orbital electrons are present on more than one nuclei depending upon the number of atoms in the molecule
• d) All of these

Answer: While an electron in an atomic orbital is influenced by one nucleus, in a molecular orbital it is influenced by two or more nuclei depending upon the number of atoms in the molecule

Question: With increasing bond order, stability of bond

• a) Increases
• b) Remain unaltered
• c) Decreases
• d) None of these

Answer: Increases

Question:

• a) O₂
• b) C₂
• c) B₂
• d) N₂

Answer: O₂

Question: Which of the following corresponds unstable molecule? Here N_b is number of bonding electrons and N_a is number of antibonding electrons.

• a) Both
• b)

  

• c)

  

• d) None of these

Answer: Both

Question:  If N_x is the number of bonding orbitals of an atom and N_y is the number of antibonding orbitals, then the molecule/atom will be stable if

• a)

  

• b)

  

• c)

  

• d) All of these

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: The theory capable of explaining paramagnetic behaviour of oxygen is

• a) molecular orbital theory
• b) valence bond energy
• c) V.S.E.P.R. theory
• d) resonance theory

Answer: molecular orbital theory

Question: In an anti-bonding molecular orbital, electron density is minimum

• a) between the two nuclei of the molecule
• b) around one atom of the molecule
• c) at the region away from the nuclei of the molecule
• d) at no place

Answer: between the two nuclei of the molecule

Question: When two atomic orbitals combine, they form

• a) two molecular orbital
• b) four molecular orbital
• c) one molecular orbital
• d) three molecular orbital

Answer: two molecular orbital

Question: Paramagnetism is exhibited by molecules

• a) containing unpaired electrons
• b) carrying a positive charge
• c) containing only paired electrons
• d) not attracted into a magnetic field

Answer: containing unpaired electrons

Question: The difference in energy between the molecular orbital formed and the combining atomic orbitals is called

• a) stabilization energy
• b) bond energy
• c) activation energy
• d) destabilization energy

Answer: stabilization energy

Question:

• a) 2.5
• b) 1.5
• c) 3.0
• d) 2.0

Answer: 2.5

Question: Which molecule has the highest bond order?

• a) N₂
• b) He₂
• c) Li₂
• d) O₂

Answer: N₂

Question: Which one of the following molecules is expected to exhibit diamagnetic behaviour ?

• a) C₂
• b) O₂
• c) N₂
• d) S₂

Answer: C₂

Question:

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: Mark the incorrect statement in the following

• a) the bond energy in a diatomic molecule always increases when an electron is lost
• b) electrons in antibonding M.O. contribute to repulsion between two atoms.
• c) with increase in bond order, bond length decreases and bond strength increases.
• d) None of these

Answer: the bond energy in a diatomic molecule always increases when an electron is lost

Question: According to molecular orbital theory which of the following statement about the magnetic character and bond order is correct regarding

• a) Paramagnetic and Bond order > O₂
• b) Diamagnetic and Bond order < O₂
• c) Diamagnetic and Bond order > O₂
• d) Paramagnetic and Bond order < O₂

Answer: Paramagnetic and Bond order > O₂

Question: Bond order is a concept in the molecular orbital theory. It depends on the number of electrons in the bonding and antibonding orbitals. Which of the  following statements is true about it ? The bond order

• a) can assume any positive or integral or fractional value including zero
• b) is a non-zero quantity
• c) has always an integral value
• d) can have a negative quantity

Answer: can assume any positive or integral or fractional value including zero

Question: Which of the following does not exist on the basis of molecular orbital theory ?

• a)

  

• b)

  

• c)

  

• d) All of these

Answer:

Question: The paramagnetic property of the oxygen molecule is due to the presence of unpaired electrons present in

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: In which of the following state of compound the magnitude of H-bonding will be maximum and in which case it will be minimum ?

• a) Maximum = Solid, Minimum = Gas
• b) Maximum = Gas, Minimum = Solid
• c) Maximum = Liquid, Minimum = Gas
• d) Maximum = Solid, Minimum = Liquid

Answer: Maximum = Solid, Minimum = Gas

Question: Which of the following are correctly classified ?

• a)

  

  

• b)

  

   

• c)

  

   

• d) None of these

Answer:

Question: Intramolecular hydrogen bond exists in

• a) ortho nitrophenol
• b) water
• c) diethyl ether
• d) ethyl alcohol

Answer: ortho nitrophenol

Question: The boiling point of p-nitrophenol is higher than that of o-nitrophenol because

• a) there is intermolecular hydrogen bonding in p-nitrophenol
• b) p-nitrophenol has a higher molecular weight than o-nitrophenol.
• c) intramolecular hydrogen bonding exists in p-nitrophenol
• d) NO₂ group at p-position behave in a different way from that at o-position.

Answer: there is intermolecular hydrogen bonding in p-nitrophenol

Question: Which one of the following is the correct order of interactions ?

• a) vander Waals < hydrogen bonding < dipole < covalent
• b) vander Waals < dipole-dipole < hydrogen bonding < covalent
• c) Dipole-dipole < vander Waals < hydrogen bonding < covalent.
• d) Covalent < hydrogen bonding < vander Waals < dipoledipole

Answer: vander Waals < hydrogen bonding < dipole < covalent

Question: Strongest hydrogen bond is shown by

• a) hydrogen fluoride
• b) water
• c) ammonia
• d) hydrogen sulphide

Answer: hydrogen fluoride

Question: The low density of ice compared to water is due to

• a) hydrogen bonding interactions
• b) dipole-dipole interactions
• c) dipole-induced dipole interactions
• d) induced dipole-induced dipole interactions

Answer: hydrogen bonding interactions

Question: Methanol and ethanol are miscible in water due to

• a) hydrogen bonding character
• b) oxygen bonding character
• c) None of these
• d) covalent character

Answer: hydrogen bonding character

Question: The hydrogen bond is shortest in

• a) F — H --- F
• b) N — H --- O
• c) S — H --- S
• d) S — H --- O

Answer: F — H --- F

Question: Hydrogen bonding is maximum in

• a) C₂H₅OH
• b) CH₃OCH₃
• c) CH₃CHO
• d) All of these

Answer: C₂H₅OH

Question:

• a) H-bonding
• b) dipole moment
• c) dipole-dipole interaction
• d) lattice structure

Answer: H-bonding

Question: The reason for exceptionally high boiling point of water is

• a) hydrogen bonding in the molecules of water
• b) low ionization of water molecule
• c) its high dielectric constant
• d) its high specific heat

Answer: hydrogen bonding in the molecules of water

Question: Acetic acid exists as dimer in benzene due to

• a) hydrogen bonding
• b) condensation reaction
• c) presence of carboxyl group
• d) presence of hydrogen atom

Answer: hydrogen bonding

Question: Hydrogen bonding is formed in compounds containing hydrogen and

• a) highly electronegative atoms
• b) highly electropositive atoms
• c) metal atoms with d-orbitals occupied
• d) metalloids

Answer: highly electronegative atoms

Question: Read the following statements and choose the correct sequence of T and F from the given codes. Here T represents true and F represents false statement.

(i) The number of dots in Lewis symbol represents the number of valence electrons.
(ii) Number of valence electrons helps to calculate group valence of element.
(iii) Group valence is given as 8 minus the number of inner shell electrons.

• a) T T F
• b) T T T
• c) T F F
• d) F F F

Answer: T T F