Problem 64
Which of the following is not characteristic of a covalent bonding? (1) s-orbital never participates in \(\pi\) bonding (2) it is effective only at small internuclear distances (3) it is directional (4) it is weaker than Van der Waal's bonding
Problem 65
Which of the following about covalent bond is false? (1) energy is required to break a covalent bond (2) covalent bonds involve overlap of orbitals (3) covalent bonds are generally stronger than the ionic bonds (4) covalent bonds are not formed by small atoms
Problem 66
Which has the planar structure? (1) \(\mathrm{NH}_{4}{ }^{\prime}\) (2) \(\mathrm{SCl}_{4}\) (3) \(\mathrm{XeF}_{4}\) (4) \(\mathrm{BF}_{4}\)
Problem 67
The molecule/ion which is not planar is (1) \(\mathrm{BF}_{3}\) (2) \(\mathrm{NO}_{3}\) (3) \(\mathrm{CO}_{3}^{2}\) (4) \(\mathrm{NF}_{3}\)
Problem 68
Which does not use \(s p^{3}\) hybrid orbitals in its bonding? (1) \(\mathrm{BF}_{3}\) (2) \(\mathrm{H}_{3} \mathrm{O}^{\prime}\) (3) \(\mathrm{NH}_{4}\) (4) \(\mathrm{NF}_{3}\)
Problem 70
The molecule which is not linear is (1) \(\mathrm{CO}_{2}\) (2) \(\mathrm{BeCl}_{2}\) (3) \(\mathrm{Cl}_{2} \mathrm{O}\) (4) \(\mathrm{IIgCl}_{2}\)
Problem 71
Which has the lowest bond angle? (1) \(\mathrm{BeF}_{2}\) (2) \(\mathrm{H}_{2} \mathrm{O}\) (3) \(\mathrm{NH}_{3}\) (4) \(\mathrm{CH}_{4}\)
Problem 72
The type of hybridisation present in \(\mathrm{SO}_{2}\) and \(\mathrm{SO}_{3}\) is respectively (1) \(\mathrm{sp}, \mathrm{sp}^{2}\) (2) \(\mathrm{sp}^{2}, \mathrm{sp}^{2}\) (3) \(\mathrm{sp}^{2}, \mathrm{sp}^{3}\) (4) \(\mathrm{sp}, \mathrm{sp}^{3}\)
Problem 73
Which statement is wrong? (1) IIybridisation is the mixing of atomic orbitals prior to thcir combining into molecular orbitals. (2) sp \(^{2}\) hybrid orbitals are formed from two \(\mathrm{p}\) - and one s-atomic orbitals. (3) sp \(^{3} \mathrm{~d}\) hybrid orbitals are all at \(90^{\circ}\) to one another. (4) \(\mathrm{sp}^{3} \mathrm{~d}^{2}\) hybrid orbitals are directed towards the corners of the regular octahedron.
Problem 74
\(\mathrm{PCH}_{5}\) exists but \(\mathrm{NCl}_{5}\) does not exist because (1) Nitrogen has no vacant \(2 \mathrm{~d}\) -orbitals. (2) NCls is unstable. (3) Nitrogen atom is much smaller than p. (4) Nitrogen is highly inert.
