JEE Chemistry Chemical Bonding and Molecular Structure MCQs Set 03

Question. Choose the correct sequence of T and F for following statements. Here T stands for true statement and F standsfor false statement.
(i) Formal charge in the Lewis structure helps in keeping track of the valence electrons in the molecule.
(ii) Formal charge indicates the actual charge separation within the molecule.
(iii) Formal charges help in the selection of the lowest energy structure from a number of possible Lewis structures.
(a) T F T
(b) F T T
(c) T T F
(d) T T T

Answer: A

Question. Read the following statements and choose the correct option. Here T stands for True and F stands for False statement.
(i) The smaller the size of the cation and the larger the size of the anion, the greater the covalent characterof an ionic bond.
(ii) The smaller the charge on the cation, the greater the covalent character of the ionic bond.
(iii) For cations of the same size and charge, the one, with electronic configuration (n ^{– 1})dⁿns⁰, typical of transition metals, is more polarising than the one with a noble gas configuration, ns² np⁶, typical of alkali and alkaline earth metal cations.
(a) T F T
(b) T T T
(c) T T F
(d) F T T

Answer: A

Question. Which of the following statements is/are not correct for combination of atomic orbitals?
(i) The combining atomic orbitals must have the same or nearly the same energy.
(ii) Greater the extent of overlap, the greater will be the electron density between the nuclei of a moleculer orbital.
(iii) 2p_z orbital of one atom can combine with either of 2p_x, 2p_y or 2p_z orbital of other atom as these orbitals have same energy.
(a) (iii) only
(b) (ii) and (iii)
(c) (i) and (ii)
(d) (i) only

Answer: A

Question. Assertion : Atoms can combine either by transfer of valence of electrons from one atom to another or by sharing of valence electrons.
Reason : Sharing and transfer of valence electrons is done by atoms to have an octet in their valence shell.
(a) Assertion is correct, reason is correct; reason is a correct explanation for assertion
(b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(c) Assertion is correct, reason is incorrect
(d) Assertion is incorrect, reason is correct

Answer: A

Question. Assertion : The lesser the lattice enthalpy more stable is the ionic compound.
Reason : The lattice enthalpy is greater, for ions of highest charge and smaller radii.
(a) Assertion is incorrect, reason is correct.
(b) Assertion is correct, reason is incorrect
(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question. Assertion : Sulphur compounds like SF6 and H2SO4 have 12 valence electrons around S atom.
Reason : All sulphur compounds do not follow octet rule.
(a) Assertion is correct, reason is incorrect
(b) Assertion is incorrect, reason is correct.
(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question. Assertion : BF3 molecule has zero dipole moment.
Reason : F is electronegative and B–F bonds are polar in nature.
(a) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(b) Assertion is correct, reason is incorrect
(c) Assertion is incorrect, reason is correct.
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question. Assertion : CH₂Cl₂ is non-polar and CCl₄ is polar molecule.
Reason : Molecule with zero dipole moment is non-polar in nature.
(a) Assertion is incorrect, reason is correct
(b) Assertion is correct, reason is incorrect
(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question. Assertion : Lone pair-lone pair repulsive interactions are greater than lone pair-bond pair and bond pair-bond pair interactions.
Reason : The space occupied by lone pair electrons is more as compared to bond pair electrons.
(a) Assertion is correct, reason is correct; reason is a correct explanation for assertion.
(b) Assertion is incorrect, reason is correct.
(d) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

Answer: A

Question. Assertion : In NH₃, N is sp³ hybridised, but angle is found to be 107°.
Reason : The decrease in bond angle is due to repulsion between the lone pair.
(a) Assertion is correct, reason is correct; reason is a correct explanation for assertion.
(b) Assertion is incorrect, reason is correct.
(c) Assertion is correct, reason is incorrect
(d) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

Answer: A

Question. Assertion : Shape of NH₃ molecule is tetrahedral.
Reason : In NH₃ nitrogen is sp³ hybridized
(a) Assertion is incorrect, reason is correct.
(b) Assertion is correct, reason is incorrect
(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(d) None of these

Answer: A

Question. Assertion : The bond order of helium is always zero.
Reason : The number of electrons in bonding molecular orbital and antibonding molecular orbital is equal.
(a) Assertion is correct, reason is correct; reason is a correct explanation for assertion.
(b) Assertion is incorrect, reason is correct.
(c) Assertion is correct, reason is incorrect
(d) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

Answer: A

Question. Assertion : Water is one of the best solvent.
Reason : H-bonding is present in water molecules.
(a) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(b) Assertion is correct, reason is incorrect
(c) Assertion is incorrect, reason is correct
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question. Assertion : Bonding molecular orbital has greater stability than corresponding antibonding molecular orbital.
Reason : The electron density in a bonding molecular orbital is located away from the space between the nuclei while in antibonding molecular orbital it is located between the nuclei of the bonded atoms.
(a) Assertion is correct, reason is incorrect
(b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(c) Assertion is incorrect, reason is correct
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question. Which of the following molecules has trigonal planar geometry?
(a) BF³
(b) PCl³
(c) NH³
(d) IF³

Answer: A

Question.  Which of the following molecules is planar?
(a) XeF₄
(b) SiF₄
(c) SF₄
(d) NF₃

Answer: A

Question.  Hybridization present in ClF₃ is
(a) sp³d
(b) sp³
(c) sp²
(d) dsp²

Answer: A

Question. The type of hybridization in xenon atom and the number of lone pairs present on xenon atom in xenon hexafluoride molecule are respectively
(a) sp³d³ , one
(b) sp³d³ , two
(c) sp³d³ ,zero
(d) None of these

Answer: A

Question. If an organic compound contain 92.3% C and 7.7% H, than number of sp³,sp² and sp hybridized carbon atoms in all possible structures of compound respectively are (molecular mass = 52g/mol)
(a) 0, 8, 4
(b) 1, 2, 5
(c) 0, 4, 4
(d) None of these

Answer: A

Question. Which of the following molecule exist ?
(a) Li₂
(b) He₂
(c) Be₂
(d) None of these

Answer: A

Question. Hybridization and structure of I^3– are
(a) sp³d and linear
(b) sp³ and T-shape
(c) sp³d² and linear
(d) None of these

Answer: A

Question. Which of the following substances has the greatest ionic character ?
(a) BaCl₂
(b) NCl₃
(c) Cl₂O
(d) PbCl₂

Answer: A

Question. Among the following species, identify the pair having same bond order CN^–, O₂ ^– , NO⁺, CN⁺
(a) CN^– and NO⁺
(b) CN^– and O₂^–
(c) CN^– and CN⁺
(d) None of these

Answer: A

Question.  The molecule which has the highest bond order is
(a) N₂
(b) O₂
(c) C₂
(d) B₂

Answer: A

Question. The compound which cannot be formed is
(a) He₂
(b) He
(c) Both
(d) None of these

Answer: A

Question. Bond order in benzene is
(a) 1.5
(b) 1
(c) 2
(d) None of these

Answer: A

Question. Hydrogen bonding would not affect the boiling point of
(a) HI
(b) H₂O
(c) NH₃
(d) None of these

Answer: A

Question. Which one of the following molecules will form a linear polymeric structure due to hydrogen bonding?
(a) HF
(b) NH₃
(c) HCl
(d) H₂O

Answer: A