21381.Assuming that Hund's rule is violated, the bond order and magnetic nature of the diatomic molecule B2 is
1 and diamagnetic
0 and diamagnetic
1 and paramagnetic
0 and paramagnetic
21382.The hybridization of orbitals of N atom in NO–
3, NO+
2 and NH+
4 are respectively
3, NO+
2 and NH+
4 are respectively
sp2, sp3, sp
sp, sp2, sp3
sp2, sp, sp3
sp, sp3, sp2
21383.In acetylene molecule, between the carbon atoms there are
three sigma bonds
two sigma and one pi bonds
one sigma and two pi bonds
three pi bonds
21385.The outer orbitals of C in ethene molecule can be considered to be hybridized to give three equivalent sp2 orbitals. The total number of sigma (σ) and pi (π) bonds in ethene molecule is
1 sigma (σ) and 2 pi (π) bonds
3 sigma (σ) and 2 pi (π) bonds
4 sigma (σ) and 1 pi (π) bonds
5 sigma (σ) and 1 pi (π) bonds
21386.An atom of an element A has three electrons in its outermost orbit and that of B has six electrons in its outermost orbit. The formula of the compound between these two will be
A3B6
A2B3
A3B2
A2B
21387.Which one of the following has the regular tetrahedral structure? (Atomic numbers B = 5, S = 16, Ni = 28, Xe = 54)
XeF4
SF4
BF–
4
4
[Ni(CN)4]2–
21388.Predict the correct order among the following
bond pair - bond pair > lone pair - bond pair > lone pair - lone pair
lone pair - bond pair > bond pair - bond pair > lone pair - lone pair
lone pair - lone pair > lone pair - bond pair > bond pair - bond pair
lone pair - lone pair > bond pair - bond pair > lone pair - bond pair