Chapter 13

The molecular shapes of \(\mathrm{SF}_{4}, \mathrm{CF}_{4}\) and \(\mathrm{XeF}_{4}\) are (a) the same with 2,0 and 1 lone pairs of electrons on the central atom, respectively (b) the same with 1,1 and 1 lone pair of electrons on the central atom, respectively (c) different with 0,1 and 2 lone pairs of electrons on the central atom, respectively (d) different with 1,0 and 2 lone pairs of electrons on the central atom, respectively

The number and type of bonds between two carbon atoms in calcium carbide are (a) one sigma, two pi (b) two sigma, two pi (c) one sigma, one pi (d) two sigma, one pi

Of the following sets which does not contain isoelectronic species? (a) \(\mathrm{SO}_{3}^{2-}, \mathrm{CO}_{3}^{2-}, \mathrm{NO}_{3}^{-}\) (b) \(\mathrm{CN}^{-}, \mathrm{N}_{2}, \mathrm{C}_{2}^{2-}\) (c) \(\mathrm{BO}_{3}^{3-}, \mathrm{CO}_{3}^{2-}, \mathrm{NO}_{3}^{-}\) (d) \(\mathrm{PO}_{4}^{3-}, \mathrm{SO}_{4}^{2-}, \mathrm{ClO}_{4}^{-}\)

Which of the following molecules/ions does not contain unpaired electrons? (a) \(\mathrm{O}_{2}^{2-}\) (b) \(\mathrm{B}_{2}\) (c) \(\mathrm{N}_{2}^{+}\) (d) \(\mathrm{O}_{2}\)

In which of the following molecules/ions all the bonds are unequal? (a) \(\mathrm{SF}_{4}\) (b) \(\mathrm{SiF}_{4}\) (c) \(\mathrm{XeF}_{4}\) (d) \(\mathrm{BF}_{4}^{-}\)

In which of the following ionization processes, the bond order has increased and the magnetic behaviour has changed? (a) \(\mathrm{NO} \rightarrow \mathrm{NO}^{+}\) (b) \(\mathrm{O}_{2} \rightarrow \mathrm{O}_{2}^{+}\) (c) \(\mathrm{N}_{2} \rightarrow \mathrm{N}_{2}^{+}\) (d) \(\mathrm{C}_{2} \rightarrow \mathrm{C}_{2}^{+}\)

Which of the following hydrogen bonds is the strongest? \(\quad\) (a) \(\mathrm{F}-\mathrm{H} \ldots . \mathrm{F}\) (b) \(\mathrm{O}-\mathrm{H} \ldots \mathrm{O}\) (c) \(\mathrm{O}-\mathrm{H} \ldots \mathrm{F}\) (d) \(\mathrm{O}-\mathrm{H}_{\ldots} . \mathrm{N}\)

Which of the following species exhibits the diamagnetic behaviour? (a) \(\mathrm{O}_{2}^{+}\) (b) \(\mathrm{O}_{2}\) (c) NO (d) \(\mathrm{O}_{2}^{2-}\)

The charge/size ratio of a cation determines its polarizing power. Which one of the following sequences represents the increasing order of the polarizing power of the cationic species, \(\mathrm{K}^{+}, \mathrm{Ca}^{2+}, \mathrm{Mg}^{2+}, \mathrm{Be}^{2+}\) ? (a) \(\mathrm{Be}^{2+}<\mathrm{K}^{+}<\mathrm{Ca}^{2+}<\mathrm{Mg}^{2+}\) (b) \(\mathrm{K}^{+}<\mathrm{Ca}^{2+}<\mathrm{Mg}^{2+}<\mathrm{Be}^{2+}\) (c) \(\mathrm{Ca}^{2+}<\mathrm{Mg}^{2+}<\mathrm{Be}^{2+}<\mathrm{K}^{+}\) (d) \(\mathrm{Mg}^{2+}<\mathrm{Be}^{2+}<\mathrm{K}^{+}<\mathrm{Ca}^{2+}\)

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