Chapter 4

The hydrogen bond is strongest in : (a) \(\mathrm{O}-\mathrm{H} \ldots \ldots \ldots \mathrm{S}\) (b) \(\mathrm{S}-\mathrm{H} \ldots \ldots \ldots \mathrm{O}\) (c) \(\mathrm{F}-\mathrm{H} \ldots \ldots \ldots \mathrm{F}\) (d) \(\mathrm{F}-\mathrm{H}, \ldots \ldots \ldots \mathrm{O}\)

Draw the structure of \(\mathrm{XeF}_{4}\) and \(\mathrm{OSF}_{4}\) according to VSEPR theory, clearly indicating the state of hybridisation of the central atom and lone pair of electrons (if any) on the central atom.

The molecule having one unpaired electron is: (a) NO (b) \(\mathrm{CO}\) (c) \(\mathrm{CN}^{-}\) (d) \(\mathrm{O}_{2}\)

Using VSEPR theory, draw the shape of \(\mathrm{PCl}_{5}\) and \(\mathrm{BrF}_{5}\).

On hybridization of one \(s\) and one \(p\) orbitals we get : (a) two mutually perpendicular orbitals (b) two orbitals at \(180^{\circ}\) (c) four orbitals directed tetrahedrally (d) three orbitals in a plane

Interpret the non-linear shape of \(\mathrm{H}_{2} \mathrm{~S}\) molecule and non-planar shape of \(\mathrm{PCl}_{3}\) using valence shell electron pair repulsion (VSEPR) theory. (Atomic numbers : \(\mathrm{H}=1, \mathrm{P}=15, \mathrm{~S}=16, \mathrm{Cl}=17 .\) )

Which one among the following does not have the hydrogen bond? [1983-1 Mark] (a) phenol (b) liquid \(\mathrm{NH}_{3}\) (c) water (d) liquid \(\mathrm{HCl}\)

Using the VSEPR theory, identify the type of hybridization and draw the structure of \(\mathrm{OF}_{2}\). What are the oxidation states of \(\mathrm{O}\) and \(\mathrm{F}\) ?

Among the following, the molecule that is linear is (a) \(\mathrm{CO}_{2}\) (b) \(\mathrm{NO}_{2}\) (c) \(\mathrm{SO}_{2}\) (d) \(\mathrm{ClO}_{2}\)

Among \(\mathrm{H}_{2}, \mathrm{He}_{2}^{+}, \mathrm{Li}_{2}, \mathrm{Be}_{2}, \mathrm{~B}_{2}, \mathrm{C}_{2}, \mathrm{~N}_{2}, \mathrm{O}_{2}\) and \(\mathrm{F}_{2}\), the number of diamagnetic species is (Atomic numbers: \(\mathrm{H}=1, \mathrm{He}=2, \mathrm{Li}=3, \mathrm{Be}=4, \mathrm{~B}=5, \mathrm{C}=6, \mathrm{~N}=7, \mathrm{O}=8\), \(\mathrm{F}=9\) )

hybrid orbitals of nitrogen atom are involved in the formation of ammonium ion.

Pair of molecules which forms strongest intermolecular hydrogen bond is ............... \(\left(\mathrm{SiH}_{4}\right.\) and \(\mathrm{SiF}_{4}, \mathrm{CH}_{3}-\stackrel{\mathrm{C}}{\mathrm{O}}-\mathrm{CH}_{3}\) and \(\mathrm{CHCl}_{3}, \mathrm{H}-\stackrel{\mathrm{C}}{\mathrm{O}}-\mathrm{OH}\) and \(\mathrm{CH}_{3}-\stackrel{\mathrm{C}}{\mathrm{O}}-\) OH

Which of the following have identical bond order? (a) \(\mathrm{CN}^{-}\) (b) \(\mathrm{O}_{2}^{-}\) (c) \(\mathrm{NO}^{+}\) (d) \(\mathrm{CN}^{+}\)

Write the M.O. electron distribution of \(\mathrm{O}_{2}\). Specify its bond order and magnetic property.

Arrange the following : (i) \(\mathrm{N}_{2}, \mathrm{O}_{2}, \mathrm{~F}_{2}, \mathrm{Cl}_{2}\) in increasing order of bond dissociation energy. [1988-1 Mark] (ii) Increasing strength of hydrogen bonding \((\mathrm{X}-\mathrm{H}-\mathrm{X})\) : [1991-1 Mark] \(\mathrm{O}, \mathrm{S}, \mathrm{F}, \mathrm{Cl}, \mathrm{N}\) (iii) In the decreasing order of the \(\mathrm{O}-\mathrm{O}\) bond length present in them $$ \mathrm{O}_{2}, \mathrm{KO}_{2} \text { and } \mathrm{O}_{2}\left[\mathrm{AsF}_{4}\right] $$

How many sigma bonds and how many pi-bonds are present in a benzene molecule?