Chapter 4

The dipole moments of \(\mathrm{CCl}_{4}, \mathrm{CHCl}_{3}\) and \(\mathrm{CH}_{4}\) are in the order: [Main Jan. 07, 2020 (I)] (a) \(\mathrm{CHCl}_{3}<\mathrm{CH}_{4}=\mathrm{CCl}_{4}\) (b) \(\mathrm{CCl}_{4}<\mathrm{CH}_{4}<\mathrm{CHCl}_{3}\) (c) \(\mathrm{CH}_{4}<\mathrm{CCl}_{4}<\mathrm{CHCl}_{3}\) (d) \(\mathrm{CH}_{4}=\mathrm{CCl}_{4}<\mathrm{CHCl}_{3}\)

The compound that has the largest \(\mathrm{H}-\mathrm{M}-\mathrm{H}\) bond angle \((\mathrm{M}=\mathrm{N}, \mathrm{S},\), C), is: (a) \(\mathrm{H}_{2} \mathrm{O}\) (b) \(\mathrm{NH}_{3}\) (c) \(\mathrm{H}_{2} \mathrm{~S}\) (d) \(\mathrm{CH}_{4}\)

Which of the following compounds contain(s) no covalent bond(s)? \(\mathrm{KCl}, \mathrm{PH}_{3}, \mathrm{O}_{2}, \mathrm{~B}_{2} \mathrm{H}_{6}, \mathrm{H}_{2} \mathrm{SO}_{4}\) [Main 2018] (a) \(\mathrm{KCl}, \mathrm{B}_{2} \mathrm{H}_{6}, \mathrm{PH}_{3}\) (b) \(\mathrm{KCl}, \mathrm{H}_{2} \mathrm{SO}_{4}\) (c) \(\mathrm{KCl}\) (d) \(\mathrm{KCl}, \mathrm{B}_{2} \mathrm{H}_{6}\)

The molecule in which hybrid MOs involve only one \(d\)-orbital of the central atom is : (a) \(\left[\mathrm{Ni}(\mathrm{CN})_{4}\right]^{2-}\) (b) \(\mathrm{BrF}_{5}\) (c) \(\mathrm{XeF}_{4}\) (d) \(\left[\mathrm{CrF}_{6}\right]^{3-}\)

The structure of \(\mathrm{PCl}_{5}\) in the solid state is: (a) tetrahedral \(\left[\mathrm{PCl}_{4}\right]^{+}\)and octahedral \(\left[\mathrm{PCl}_{6}\right]^{-}\) (b) square planar \(\left[\mathrm{PCl}_{4}\right]^{+}\)and octahedral \(\left[\mathrm{PCl}_{6}\right]^{-}\) (c) square pyramidal (d) trigonal bipyramidal

If \(\mathrm{AB}_{4}\) molecule is a polar molecule, a possible geometry of \(\mathrm{AB}_{4}\) is : (a) Square pyramidal (b) Tetrahedral (c) Rectangular planar (d) Sauare planar

Of the species, \(\mathrm{NO}, \mathrm{NO}^{+}, \mathrm{NO}^{2+}\) and \(\mathrm{NO}^{-}\), the one with minimum bond strength is: [Main Sep. \(\mathbf{0 3}, \mathbf{2 0 2 0}\) (I)] (a) \(\mathrm{NO}^{+}\) (b) \(\mathrm{NO}\) (c) \(\mathrm{NO}^{2+}\) (d) \(\mathrm{NO}^{-}\)

Which of these statements is not true? [Main Online April 19, 2014] (a) \(\mathrm{NO}^{+}\)is not isoelectronic with \(\mathrm{O}_{2}\) (b) \(\mathrm{B}\) is always covalent in its compounds (c) In aqueous solution, the \(\mathrm{Tl}^{+}\)ion is much more stable than Tl (III) (d) \(\mathrm{LiAlH}_{4}\) is a versatile reducing agent in organic synthesis.

The shape/ structure of \(\left[\mathrm{XeF}_{5}\right]^{-}\)and \(\mathrm{XeO}_{3} \mathrm{~F}_{2}\), respectively, are : (a) pentagonal planar and trigonal bipyramidal (b) octahedral and square pyramidal (c) trigonal bipyramidal and pentagonal planar (d) trigonal bipyramidal and trigonal bipyramidal

If the magnetic moment of a dioxygen species is \(1.73\) B.M, it may be: [Main Jan. 09, 2020 (I)] (a) \(\mathrm{O}_{2}^{-}\)or \(\mathrm{O}_{2}^{+}\) (b) \(\mathrm{O}_{2}\) or \(\mathrm{O}_{2}^{+}\) (c) \(\mathrm{O}_{2}\) or \(\mathrm{O}_{2}^{-}\) (d) \(\mathrm{O}_{2}, \mathrm{O}_{2}^{-}\)or \(\mathrm{O}_{2}^{+}\)

The correct order of bond dissociation energy among \(\mathrm{N}_{2}, \mathrm{O}_{2}, \mathrm{O}_{2}^{-}\)is shown in which of the following arrangements? (a) \(\mathrm{N}_{2}>\mathrm{O}_{2}^{-}>\mathrm{O}_{2}\) (b) \(\mathrm{O}_{2}^{-}>\mathrm{O}_{2}>\mathrm{N}_{2}\) (c) \(\mathrm{N}_{2}>\mathrm{O}_{2}>\mathrm{O}_{2}^{-}\) (d) \(\mathrm{O}_{2}>\mathrm{O}_{2}^{-}>\mathrm{N}_{2}\)

The molecular geometry of \(\mathrm{SF}_{6}\) is octahedral. What is the geometry of \(\mathrm{SF}_{4}\) (including lone pair(s) of electrons, if any)? (a) Tetrahedral (b) Trigonal bipyramidal (c) Pyramidal (d) Square planar

The bond order and the magnetic characteristics of \(\mathrm{CN}^{-}\)are: [Main Jan. 07, 2020 (II)] (a) \(2 \frac{1}{2}\), diamagnetic (b) 3 , diamagnetic (c) 3, paramagnetic (d) \(2 \frac{1}{2}\), paramagnetic

Which one of the following molecules is polar ? [Main Online April 9, 2013] (a) \(\mathrm{XeF}_{4}\) (b) \(\mathrm{IF}_{5}\) (c) \(\mathrm{SbF}_{5}\) (d) \(\mathrm{CF}_{4}\)

The correct statement about \(\mathrm{ICl}_{5}\) and IClis : (a) both are is isostructural. (b) \(\mathrm{ICl}_{5}\) is trigonal bipyramidal and \(\mathrm{ICl}_{4}\) is tetrahedral. (c) \(\mathrm{ICl}_{5}\) is square pyramidal and \(\mathrm{ICl}_{4}^{-}\)is tetrahedral. (d) \(\mathrm{ICl}_{5}\) is square pyramidal and \(\mathrm{ICl}_{4}^{-}\)is square planar.

Among the following, the molecule expected to be stabilised by anion formation is: [Main April 9, 2019 (I)] \(\mathrm{C}_{2}, \mathrm{O}_{2}, \mathrm{NO}, \mathrm{F}_{2}\) (a) \(\mathrm{C}_{2}\) (b) \(\mathrm{F}_{2}\) (c) \(\mathrm{NO}\) (d) \(\mathrm{O}_{2}\)

The geometry of \(\mathrm{H}_{2} \mathrm{~S}\) and its dipole moment are [1999-2 Marks] (a) angular and non-zero (b) angular and zero (c) linear and non-zero (d) linear and zero

The ion that has \(s p^{3} d^{2}\) hydridisation for the central atom, is: (a) \(\left[\mathrm{ICl}_{4}\right]^{-}\) (b) \(\left[\mathrm{ICl}_{2}\right]^{-}\) (c) \(\left[\mathrm{IF}_{6}\right]^{-}\) (d) \(\left[\mathrm{BrF}_{2}\right]^{-}\)

Among the following species, the diamagnetic molecule is: [Main April 9, 2019 (II)] (a) NO (b) \(\mathrm{CO}\) (c) \(\mathrm{B}_{2}\) (d) \(\mathrm{O}_{2}\)

The critical temperature of water is higher than that of \(\mathrm{O}_{2}\) because the \(\mathrm{H}_{2} \mathrm{O}\) molecule has [1997 - 1 Mark] (a) fewer electrons than \(\mathrm{O}_{2}\) (b) two covalent bonds (c) V-shape (d) dipole moment.

Total number of lone pair of electrons in \(\mathrm{I}_{3}^{-}\)ion is : (a) 3 (a) 6 (c) 9 (d) 12

Among the following molecules/ions, \(\mathrm{C}_{2}^{2-}, \mathrm{N}_{2}^{2-}, \mathrm{O}_{2}^{2-}, \mathrm{O}_{2}\) Which one is diamagnetic and has the shortest bond length? [Main April 8, 2019 (II)] (a) \(\mathrm{O}_{2}\) (b) \(\mathrm{N}_{2}^{2-}\) (c) \(\mathrm{O}_{2}^{2-}\) (d) \(\mathrm{C}_{2}^{2-}\)

Which contains both polar and non-polar bonds? (a) \(\mathrm{NH}_{4} \mathrm{Cl}\) (b) \(\mathrm{HCN}\) (c) \(\mathrm{H}_{2} \mathrm{O}_{2}\) (d) \(\mathrm{CH}_{4}\)

The incorrect geometry is represented by (a) \(\mathrm{NF}_{3}\) - trigonal planar (b) \(\mathrm{BF}_{3}\) - trigonal planar (c) AsF \(_{5}\) - trigonal bipyramidal (d) \(\mathrm{H}_{2} \mathrm{O}\) - bent

Two pi and half sigma bonds are present in: (a) \(\mathrm{O}_{2}^{+}\) (b) \(\mathrm{N}_{2}\) (c) \(\mathrm{O}_{2}\) (d) \(\mathrm{N}_{2}^{+}\)

Which one is most ionic : (a) \(\mathrm{P}_{2} \mathrm{O}_{5}\) (b) \(\mathrm{CrO}_{3}\) (c) \(\mathrm{MnO}\) (d) \(\mathrm{Mn}_{2} \mathrm{O}_{7}\)

Identify the pair in which the geometry of the species is T-shape and square pyramidal, respectively (a) \(\mathrm{ICl}_{2}\) and \(\mathrm{ICl}_{5}\) (b) \(\mathrm{IO}_{3}^{-}\)and \(\mathrm{IO}_{2} \mathrm{~F}_{2}\) (c) \(\mathrm{ClF}_{3}\) and \(\mathrm{IO}_{4}\) (d) \(\mathrm{XeOF}_{2}\) and \(\mathrm{XeOF}_{4}\)

According to molecular orbital theory, which of the following is true with respect to \(\mathrm{Li}_{2}^{+}\)and \(\mathrm{Li}_{2}^{-} ?\) [Main Jan. 9, 2019 (I)] (a) \(\mathrm{Li}_{2}^{+}\)is unstable and \(\mathrm{Li}_{2}^{-}\)is stable (b) \(\mathrm{Li}_{2}^{+}\)is stable and \(\mathrm{Li}_{2}^{-}\)is unstable (c) Both are stable (d) Both are unstable

Pick out the isoelectronic structures from the following; [1993-1 Mark] \(\begin{array}{llllllll}\text { I. } & \mathrm{CH}_{3}^{+} & \text {II. } \mathrm{H}_{3} \mathrm{O}^{+} & \text {III. } \mathrm{NH}_{3} & \mathrm{IV} & \mathrm{CH}_{3}^{-}\end{array}\) (a) I and II (b) III and IV (c) I and III (d) II, III and IV

$$ s p^{3} d^{2} \text { Hybridisation is not displayed by : } $$ (a) \(\mathrm{BrF}_{5}\) (b) \(\mathrm{SF}_{6}\) (c) \(\left[\mathrm{CrF}_{6}\right]^{3-}\) (d) \(\mathrm{PF}_{5}\)

According to molecular orbital theory, which of the following will not be a viable molecule? [Main 2018] (a) \(\mathrm{He}_{2}^{2+}\) (b) \(\mathrm{He}_{2}^{+}\) (c) \(\mathrm{H}_{2}^{-}\) (d) \(\mathrm{H}_{2}^{2-}\)

The cyanide ion, \(\mathrm{CN}^{-}\)and \(\mathrm{N}_{2}\) are isoelectronic. But in contrast to \(\mathrm{CN}^{-}\), \(\mathrm{N}_{2}\) is chemically inert, because of [1992 - 1 Mark] (a) low bond energy (b) absence of bond polarity (c) unsymmetrical electron distribution (d) presence of more number of electrons in bonding orbitals

The species in which the \(\mathrm{N}\) atom is in a state of \(s p\) hybridisation is : (a) \(\mathrm{NO}_{3}^{-}\) (b) \(\mathrm{NO}_{2}\) (c) \(\mathrm{NO}_{2}^{+}\) (d) \(\mathrm{NO}_{2}^{-}\)

(I) (II) \(\mathrm{H}-\mathrm{N}--\mathrm{N}--\mathrm{N}\) In hydrogen azide, the bond orders of bonds (I) and (II) are [Main Online April 15, 2018 (I)] (a) \(\mathrm{I}<2, \mathrm{II}>2\) (b) \(\mathrm{I}>2, \mathrm{II}>2\) (c) \(\mathrm{I}>2, \mathrm{II}<2\) (d) \(\mathrm{I}<2, \mathrm{II}<2\)

The molecule which has zero dipole moment is : (a) \(\mathrm{CH}_{2} \mathrm{Cl}_{2}\) (b) \(\mathrm{BF}_{3}\) (c) \(\mathrm{NF}_{3}\) (d) \(\mathrm{ClO}_{2}\)

The group of molecules having identical shape is : (a) \(\mathrm{PCl}_{5}, \mathrm{IF}_{5}, \mathrm{XeO}_{2} \mathrm{~F}_{2}\) (b) \(\mathrm{BF}_{3}, \mathrm{PCl}_{3}, \mathrm{XeO}_{3}\) (c) \(\mathrm{SF}_{4}, \mathrm{XeF}_{4}, \mathrm{CCl}_{4}\) (d) \(\mathrm{ClF}_{3}, \mathrm{XeOF}_{2}, \mathrm{XeF}_{3}^{+}\)

The bond between two identical non-metal atoms has a pair of electrons: [1986-1 Mark] (a) unequally shared between the two (b) transferred fully from one atom to another (c) with identical spins (d) equally shared between them

Which of the following is paramagnetic ? [Main Online April 8, 2017] (a) \(\mathrm{NO}^{+}\) (b) \(\mathrm{CO}\) (c) \(\mathrm{O}_{2}^{2-}\) (d) \(\mathrm{B}_{2}\)

The types of bonds present in \(\mathrm{CuSO}_{4} .5 \mathrm{H}_{2} \mathrm{O}\) are only (a) electrovalent and covalent [1983 - 1 Mark] (b) electrovalent and coordinate covalent (c) electrovalent, covalent and coordinate covalent (d) covalent and coordinate covalent

The shape of \(\mathrm{IF}_{6}\) is : (a) Trigonally distorted octahedron (b) Pyramidal (c) Octahedral (d) Square antiprism

Which of the following species is not paramagnetic ? (a) \(\mathrm{NO}\) (b) \(\mathrm{CO}\) (c) \(\mathrm{O}_{2}\) (d) \(\mathrm{B}_{3}\)

Carbon tetrachloride has no net dipole moment because of [1983-1 Mark] (a) its planar structure (b) its regular tetrahedral structure (c) similar sizes of carbon and chlorine (d) similar electron affinities of carbon and chlorine

The species having pyramidal shape is : (a) \(\mathrm{SO}_{3}\) (b) \(\mathrm{BrF}_{3}\) (c) \(\mathrm{SiO}_{3}^{2-}\) (d) \(\mathrm{OSF}_{2}\)

The compound with no dipole moment is (a) methyl chloride (b) carbon tetrachloride (c) methylene chloride (d) chloroform

Which species has the maximum number of lone pair of electrons on the central atom? (a) \(\left[\mathrm{ClO}_{3}\right]^{-}\) (b) \(\mathrm{XeF}_{4}\) (c) \(\mathrm{SF}_{4}\) (d) \(\left[\mathrm{I}_{3}\right]^{-}\)

Which one of the following properties is not shown by NO? [Main 2014] (a) It is diamagnetic in gaseous state (b) It is neutral oxide (c) It combines with oxygen to form nitrogen dioxide (d) Its bond order is \(2.5\)

The ion that is isoelectronic with \(\mathrm{CO}\) is (a) \(\mathrm{CN}^{-}\) (b) \(\mathrm{O}_{2}^{+}\) (c) \(\mathrm{O}_{2}^{-}\) (d) \(\mathrm{N}_{2}^{+}\)

Which one of the following molecules is paramagnetic? [Main Online April 19, 2014] (a) \(\mathrm{N}_{2}\) (b) NO (c) \(\mathrm{CO}\) (d) \(\mathrm{O}_{3}\)

If a molecule \(M X_{3}\) has zero dipole moment, the sigma bonding orbitals used by \(M\) (atomic number \(<21\) ) are [1981 - 1 Mark] (a) pure \(p\) (b) \(s p\) hybrid (c) \(s p^{2}\) hybrid (d) \(s p^{3}\) hybrid

Specify the coordination geometry around and hybridisation of \(\mathrm{N}\) and B atoms in a \(1: 1\) complex of \(\mathrm{BF}_{3}\) and \(\mathrm{NH}_{3}\) (a) \(\mathrm{N}\) : tetrahedral, \(s p^{3} ; \mathrm{B}:\) tetrahedral, \(s p^{3}\) (b) \(\mathrm{N}:\) pyramidal,\(s p^{3} ; \mathrm{B}:\) pyramidal,\(s p^{3}\) (c) \(\mathrm{N}\) : pyramidal, \(s p^{3} ; \mathrm{B}\) : planar, \(s p^{2}\) (d) \(\mathrm{N}\) : pyramidal, \(s p^{3} ; \mathrm{B}\) : tetrahedral, \(s p^{3}\)