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
B.
F – H …… F
The hydrogen bond in HF is strongest, because fluorine is the most electronegative element.
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
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