MCQ of Chemical Bonding and Molecular Structure | Ch 4 | Chemistry |

MCQ of Chemical Bonding and Molecular Structure, Chapter 4, Chemistry, Class 11

 

Question 1: In a covalent bond formation,

  1. Transfer of electrons takes place
  2. Equal sharing of electrons between two atoms takes place
  3. Electrons are shared by one atom only
  4. Electrons are donated by one atom in shared by both atoms.

Answer: B (Equal sharing of electrons between two atoms takes place)

Question 2: During a co-ordinate bond formation

  1. One electron from an atom is transferred to other
  2. One electron each is lost from both the atoms
  3. A pair of electrons is contributed by one atom and shared by both the atoms
  4. A pair of electrons is transferred to the other atom

Answer: C (A pair of electrons is contributed by one atom and shared by both the atoms)

Question 3: How many and what type of bonds are present in NH4+?

  1. Four covalent bonds
  2. Three covalent bonds and one ionic bond
  3. Four ionic bonds
  4. Three covalent bonds and one co-ordinate bonds

Answer: D (Three covalent bonds and one co-ordinate bonds)

Question 4: Among the following the exception of the octet rule is

  1. The incomplete octet of central atom
  2. An odd number of electrons on central atom
  3. Expanded octet of the central atom
  4. All of these

Answer: D (All of these)

Question 5: Sodium chloride has a crystalline structure made up of Na+ and Cl ions. Why does NaCl not conduct electricity in the solid state?

  1. The ions of NaCl become mobile only in the molten state and are not free to move in solid state
  2. The crystalline structure does not have ions
  3. When a bond is formed between ions they lose their charges
  4. None of these

Answer: A (The ions of NaCl become mobile only in the molten state and are not free to move in solid state )

Question 6: Two elements X and Y combined to form a compound XY. Under what conditions the bond formed between them will be ionic?

  1. If the difference in electronegativity of X and Y is 1.9
  2. If the difference in electronegativity of X and Y is more than 1.9
  3. If the difference in electronegativity of X and Y is less than 1.9
  4. If both X and Y are highly electronegative

Answer: B (If the difference in electronegativity of X and Y is more than 1.9)

Question 7: The resonating structures of a molecule required to describe the structure of a molecule follows which of the following rules?

  1. The relative position of all atoms can differ.
  2. The same number of unpaired unpaired electrons in all structures
  3. The energy of each structure is different
  4. Like charges are present on adjacent atoms

Answer: B (The same number of unpaired unpaired electrons in all structures )

Question 8: Which of the following is non polar ?

  1. SO2
  2. CO2
  3. H2O
  4. NH3

Answer: B (CO2)

Question 9: According to VSEPR theory,

  1. The shape of the molecule depends upon the bonded electron pairs
  2. Pair of electrons attract each other in valence shells
  3. The pair of electrons tend to occupy such positions that minimise repulsions
  4. The pairs of electrons tend to occupy such positions that minimise distances from each other

Answer: C ( The pair of electrons tend to occupy such positions that minimise repulsions )

Question 10: Which of the following statements is correct regarding the structure of PCl5?

  1. Three P-Cl bonds lie in one plane and P-Cl bones lie above and below the equatorial plane
  2. Five P-Cl bonds lie in the same plane
  3. The bond angle in all P-Cl bonds is 90°
  4. The bond length of all P-Cl bonds is same.

Answer: A (Three P-Cl bonds lie in one plane and P-Cl bones lie above and below the equatorial plane)

You may also read MCQ of Basic Concepts of Chemistry, MCQ of Structure of Atom, MCQ of Classification of Elements and Periodicity in PropertiesMCQ of States of Matter, MCQ of Redox Reactions, MCQ of Hydrogen, MCQ of Organic Chemistry; Some Basic Principles and Techniques for better understanding of the chapters.

Question 11: In a bonded molecule, the order of repulsion between the bonded and non bonded electrons is

  1. Lone pair – lone pair > bond pair – bond pair > lone pair – bond pair
  2. Bond pair – bond pair > Lone pair – lone pair > lone pair – bond pair
  3. Lone pair – lone pair > lone pair – bond pair > Bond pair – bond pair
  4. Bond pair – bond pair > lone pair – bond pair > Lone pair – lone pair

Answer: C ( Lone pair – lone pair > lone pair – bond pair > Bond pair – bond pair)

Question 12: The shape of water molecule which should be tetrahedral as a bent or distorted tetrahedral shape with a bond angle of 104.5°. What could be the reason for this?

  1. lp-lp repulsion is more than lp-bp repulsion
  2. lp-bp repulsion is more than lp-lp repulsion
  3. lp-lp repulsion is equal to lp-bp repulsion
  4. Presence of lone pair does not affect the bond angle

Answer: A (lp-lp repulsion is more than lp-bp repulsion )

Question 13: Structure of XeF4 is

  1. Square planar
  2. Triangular
  3. Tetrahedral
  4. Octahedral

Answer: A (Square planar)

Question 14: The BCl3 is a planar molecule whereas NCl3 is pyramidal, because

  1. B-Cl bond is more polar than N-Cl bond
  2. N-Cl bond is more covalent than B-Cl bond
  3. Nitrogen atom is smaller than boron atoms
  4. BCl3 has no lone pair but NCl3 has a lone pair of electrons

Answer: D (BCl3 has no lone pair but NCl3 has a lone pair of electrons)

Question 15: Which of the following statements is not true?

  1. Ionic bonds are non directional while covalent bonds are directional
  2. Formation of π-bond shortens the distance between the two concerned atoms
  3. Ionic bond is possible between similar and dissimilar atoms
  4. Linear overlapping of atomic p-orbitals leads to a sigma bond

Answer: C (Ionic bond is possible between similar and dissimilar atoms)

Question 16: Oxygen molecule is formed by

A. One axial s-s overlap and one p-p axial overlap
B. Two p-p axial overlaps
C. Two p-p sidewise overlaps
D. One p-p axial and one p-p sidewise overlaps

Answer: D (One p-p axial and one p-p sidewise overlaps)

Question 17: Which of the following orbitals will not form sigma bond after overlapping?
A. S-orbital and S-orbital
B. S-orbital and pz-orbital
C. Pz-orbital and pz-orbital
D. px-orbital and px-orbital
Answer: D (px-orbital and px-orbital)

Question 18: Which of the following statements is true about hybridisation?
A. The hybridized orbitals have different energies for each orbital
B. The number of hybrid orbitals is equal to the number of atomic orbitals that are hybridized
C. Hybrid orbitals form multiple bonds
D. The orbitals with different energies undergo hybridization
Answer: B (The number of hybrid orbitals is equal to the number of atomic orbitals that are hybridized)

Question 19: On hybridisation of one s and three p orbitals, we get

  1. Four orbitals with tetrahedral orientation 
  2. Three orbitals with trigonal orientation
  3. Two orbitals with linear orientation
  4. Two orbitals with perpendicular orientations 

Answer: A (Four orbitals with tetrahedral orientation)

Question 20: Which of the following shows dsp2 hybridisation and a square planar geometry?

  1. SF6
  2. BrF5
  3. PCl5
  4. [Ni(CN)4]2-

Answer: D ( [Ni(CN)4]2- )

Question 21: Which of the following pairs are isostructural?

  1. SO42- and BF4
  2. NH3 and NH4+
  3. CO3 2- and CO2
  4. CH4 and BF3

Answer: A ( SO42- and BF4– )

Question 22: Given below is the bond angle in various type of hybridisation. Mark the bond angle which is not correctly matched.

  1. dsp2 – 90°
  2. sp3d2 – 90°
  3. sp3d – 90°
  4. sp3 – 109.5°

Answer: C (sp3d – 90°)

Question 23: In formation of ethene, the bond formation between s and p-orbitals takes place in which of the following manner?

  1. sp2 hybridised orbitals form sigma bond while the unhybridised (px or py) overlaps sidewise to form π bonds.
  2. sp2 hybridised orbitals form π bond while the unhybridised orbitals to form σ bond
  3. sp2 hybridised orbitals overlap with s orbitals of H atoms while unhybridised orbitals form C—C bond.
  4. sp2 hybridised orbitals form sigma bonds with H atoms while unhybridised orbitals form π bonds between C and H atoms.

Answer: A  ( sp2 hybridised orbitals form sigma bond while the unhybridised (px or py) overlaps sidewise to form π bonds. )

Question 24: The ground state configuration of S is 3s2 3p4. How does it form the compound SF6?

  1. Due to octahedral shape of S atoms
  2. Due to presence of vacant 3d-orbitals which provide 6 unpaired electrons in excited state.
  3. Due to sp3 hybridisation of S atom which provides 6 electrons to 6 F atoms.
  4. Due to presence of 3 sigma bond and 3 pi bonds between S and F. 

Answer: B ( Due to presence of vacant 3d-orbitals which provide 6 unpaired electrons in excited state. )

Question 25: Which of the following statements is not true regarding molecular orbital theory?

  1. The atomic orbitals of comparable energies combine to form molecular orbitals.
  2. An atomic orbital is monocentric while a molecular orbital is polycentric.
  3. Bonding molecular orbital has higher energy than antibonding molecular orbital.
  4. Molecular orbitals like atomic orbitals obey Aufbau principle for filling of electrons. 

Answer: C ( Bonding molecular orbital has higher energy than antibonding molecular orbital. )

Question 26: The conditions for the combination of atomic orbitals to form molecular orbitals are stated below.

  1. The combining atomic orbitals must have nearly same energy
  2. The combining atomic orbitals must overlap to maximum extent
  3. Combining atomic orbitals must have same symmetry about the molecular axis
  4. Pi (π) molecular orbitals are symmetrical around the bond axis.

Answer: D (Pi (π) molecular orbitals are symmetrical around the bond axis)

Question 27: Which of the following species has unpaired electrons?

  1. N2
  2. F2
  3. O2
  4. O22-

Answer: C (O2)

Question 28: Which of the following bond orders is indication of existence of a molecule ?

  1. Zero bond order
  2. Negative bond order
  3. Positive bond order
  4. All of these

Answer: C (Positive bond order)

Question 29: Which of the following facts regarding bond order is not valid?

  1. Bond order is given by the number of bonds between the two atoms in a molecule
  2. With increase in bond order bond enthalpy of the molecule decreases
  3. Isoelectronic molecules and ions have identical bond orders
  4. With increase in bond order, bond length decreases

Answer: B (With increase in bond order bond enthalpy of the molecule decreases)

Question 30: Hydrogen bond between two atoms is due to 

  1. Displacement of electron towards more electronegative atom resulting in fractional positive charge on hydrogen 
  2. Displacement of electrons towards hydrogen atom resulting in a polar molecule
  3. Formation of bond between hydrogen atoms of one molecule and the other.
  4. Existence of an attractive force which binds hydrogen atoms together

Answer: A (Displacement of electron towards more electronegative atom resulting in fractional positive charge on hydrogen)

Question 31: Which of the following relationships is true?

  1. Bond dissociation energy of O2 and O2¯ are same.
  2. Bond dissociation energy of O2+ is higher than O2¯.
  3. Bond dissociation energy of O2¯ and O22- are same.
  4. Bond dissociation energy of O22¯ is higher than O2¯. 

Answer: B ( Bond dissociation energy of O2+ is higher than O2¯)

Question 32: Paramagnetism is shown by the molecule which have

  1. Paired electrons
  2. Unpaired electrons
  3. Lone pair of electrons
  4. Bond order more than one

Answer: B (Unpaired electrons)

Question 33: Which of the following is true about hydrogen bonding?

  1. Cl and N have comparable electro-negativities  yet there is no H-bonding in HCl because size of Cl is large.
  2. Intermolecular hydrogen bonding results in decrease in m.pt. and b.pt.
  3. Ice has maximum density at 0°C due to H-bonding.
  4. KH2Cl2(HCl2)¯ exists but KHF2(HF2)¯ does not exist due to lack of H bonding in HCl.

Answer: A ( Cl and N have comparable electro-negativities  yet there is no H-bonding in HCl because size of Cl is large. )

Question 34: Which of the following has strongest bond?

  1. HF
  2. HCl
  3. HBr
  4. HI

Answer: A (HF)

Question 35: Though covalent in nature, methanol is soluble in water, Why?

  1. Methanol is transparent like water
  2. Due to hydrogen bonding between methanol and water molecules
  3. Due to van der Waals’ forces between methanol and water
  4. Due to covalent attraction forces

Answer: B ( Due to hydrogen bonding between methanol and water molecules )

Question 36: Which of the following statement is not true?

  1. Intermolecular hydrogen bonds are formed between two different molecules of compounds
  2. Intramolecular hydrogen bonds are formed between two different molecules of same compounds
  3. Intramolecular hydrogen bonds are formed within the same molecule
  4. Hydrogen bonds have strong influence on the physical properties of a compound 

Answer: B (Intramolecular hydrogen bonds are formed between two different molecules of same compounds)

Question 37: Which of the following statements is not correct from the view point of molecular orbital theory?

  1. Be2 is not a stable molecule
  2. He2 is not stable but He2+ is not expected to exist.
  3. Bond strength of N2 is maximum amongst the homonuclear diatomic molecules belonging to the second period.
  4. The order of energies of molecular orbitals in N2 molecule is σ2s < σ*2s < σ2pz < (π2px = π2py) < (π*2px = π*2py) < σ*2pz

Answer: D (The order of energies of molecular orbitals in N2 molecule is σ2s < σ*2s < σ2pz < (π2px = π2py) < (π*2px = π*2py) < σ*2pz )

Question 38: Select the correct statement regarding shapes of PCl5, BrF5, IF7

  1. All are square pyramidal
  2. All are trigonal pyramidal
  3. One of the given compounds is square pyramidal.
  4. One of the given compounds is tetrahedral

Answer: C (One of the given compounds is square pyramidal)

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