The bond dissociation energy of B–F in BF3 is 646 kJ 1 mol− whereas that of C-F in CF4 is 515 kJ 1 mol−.The correct reason for higher B-F bond dissociation energy as compared to that of C-F is
Smaller size of B-atom as compared to that of C- atom
Stronger σ bond between B and F in BF3 as compared to that between C and F in CF4
Significant pπ - pπ interaction between B and F in BF whereas there is no possibility of such 3 interaction between C and F in CF4
Significant pπ - pπ interaction between B and F in BF whereas there is no possibility of such 3 interaction between C and F in CF4
Which one of the following pairs of species has the same bond order?
CN− and NO+
CN− and CN+
O2− and CN−
O2− and CN−
Which of the following hydrogen bonds is the strongest?
O – H …… N
F – H …… F
O – H ….. O
O – H ….. O
Among the following mixtures, dipole-dipole as the major interaction is present in
benzene and ethanol
acetonitrile and acetone
KCl and water
KCl and water
B.
acetonitrile and acetone
Which one of the following sets of ions represents a collection of isoelectronic species?
K+ , Cl– , Ca2+, Sc3+
Ba2+, Sr2+, K+ , S2–
N3–, O2–, F– , S2–
N3–, O2–, F– , S2–
In which of the following molecules/ions are all the bonds not equal?
SF4
SiF4
XeF4
XeF4
Nickel (Z = 28) combines with a uninegative monodentate ligand X–
to form a paramagnetic complex [NiX4 ]2 −. The number of unpaired electron(s) in the nickel and geometry of this complex ion are,
respectively
one, tetrahedral
two, tetrahedral
one, square planar
one, square planar
In Fe(CO)5, the Fe – C bond possesses
π-character only
both σ and π characters
ionic character
ionic character