Types of covalent bond assignment

Types of covalent bond assignment
54. The repulsion between two lone pairs is greater than that between two bond pairs because
(a) shape of molecule determines the repulsion (b) lone pair is attracted to only one nucleus
(c) lone pair causes distortion of bond angles (d) lone pairs are formed by hybridized orbitals
55. The magnitude of repulsions between bond pairs depends on
(a) number of lone pairs on the central atom (b) shape of the molecule
(c) hybridization of central atom (d) electronegativity of central atom
56. The correct order of increasing bond angles is
57. The bond dissociation energy of a molecule is inversely proportional to
(a) extent of overlap (b) bond length
(c) bond order (d) presence of unpaired electrons
58. The total number of bonding molecular orbitals formed by LCAO is equal to
(a) total number of atomic orbitals (b) twice the atomic orbitals with nodal plane
(c) twice the number of antibonding molecular orbitals (d) half the number of atomic orbitals
60. The species having same magnetic moment as B2
is
61. In the following CN , CN
, CN, the one with the shortest bond length is
(a) CN
(b) CN (c) CN (d) both CN and CN
62. The molecule that may be destabilized by adding an electron is
(a) Nitrogen (b) H2
(c) CN (d) C2
63. The trend in boiling points of hydrides of group 15 elements shows a regular increase, while that of group 15 is
irregular because
(a) corresponding group 15 elements have small size (b) first element of group 15 has higher electronegativity
(c) first element of group 15 has lower ionization energy (d) group 15 shows irregular increase in size
64. The compounds which will not show hydrogen bonding is
(a) H3
BO3
(b) H3
PO4
Types of covalent bond assignment
(c) CH3 CHO (d) HCOOH
65. Even though both glycerol and 1 pentanol are both alcohols and have same molecular weight, glycerol is more viscous
than pentanol because
(a) glycerol had three O H covalent bonds (b) pentanol is a straight chain molecule
(c) glycerol is more polar than pentanol (d) there are two lone pairs present in oxygen of R OH
66. Even though fluorine is more electronegative than oxygen, HF has lower melting point than H2
O because
(a) HF has slightly higher molecular weight than H2
O (b) fluorine is a much smaller atom than oxygen
(c) fluorine has very low electron affinity (d) H2
O is associated with 4 hydrogen bonds per molecule
67. The electrostatic force of attraction between Na and Cl
is greater than that of Cs and Cl
because
(a) Na has higher ionization energy (b) Na does not have filled d orbitals
(c) Na has smaller size than Cs (d) Cs is more reactive than Na
68. On moving down the group the solubility of aluminium halides in aqueous solution
(a) is almost a constant (b) increases and then remains a constant
(c) increases (d) decreases