5.7 Valence Bond Theory

A Pi bond is formed by

• Overlapping of s orbital

• Overlapping of s and p orbitals

• Head-to-head overlapping of p orbitals

• Side-to-side overlapping of p orbitals

A Pi bond is stronger than Sigma bond

• True

• False

According to valence bond theory, which orbitals overlap in the formation of the bond in HBr ?

• 1s on H and 4p on Br

• 1s on H and 4s on Br

• 1s on H and 3p on Br

• 2s on H and 4p on Br

The process of mixing together 2 or more atomic orbitals that have similar energies is called .......

• Hybrid orbitals

• Hybridization

• Hybrid

• Unhybridized

Sulphur atom (SO₃) undergo ............ hybridization

• sp2

• sp3

• sp3d

• sp3d2

sp2 will form a .......

• linear and the angle is 180^o

• regular tetrahedral shape and the angles are 109.50^o

• trigonal planar with the angle 120^o

• trigonal bipyramidal

The sp3 hybrid orbitals involve

• one s orbital and three p orbitals

• one s orbital and one p orbital

• one s orbital and two p orbitals

• one s orbital, three p orbitals and one d orbital

Two carbon atom form a linear shaped ethene, C₂H_{4 ,} molecule when bonded with four other hydrogen atom. Prior to bonding, the carbon undergoes ......

• sp

• sp3

• sp3d

• sp2

For ........ , molecular geometry cannot always be accounted only s and p orbitals hybridize.

• second period and beyond

• third period and beyond

• fourth period and beyond

• fifth period and beyond

We must include d orbitals in the hybridization concept for formation of molecules with.......

i) trigonal bipyramidal

ii) trigonal planar

iii) tetrahedral shape

iv) octahedral geometries

• i only

• ii and iii

• i and iv

• ii only