Chemical Bonding - True or False Type

1. Linear overlap of two atomic p-orbitals leads to a sigma bond. (JEE 1983)

True

2. The H-N-H bond angle in NH3 is greater than the H-As-H bond angle in AsH3.

True

Reason: Repulsion is more in NH3 which makes the bond angle greater than in AsH3.

3. All molecules with polar bonds have dipole moment. (JEE 1985)

False.

Reason; If symmetrical arrangement of atoms is there, there is no dipole moment. Example CCl4.

4. SnCl2 is nonlinear molecule. (JEE 1985)
True

There is a lone pair in the bond. Due to repulsion between Lone pair and bonding pair, the bond angle less than 180°.

5. sp² hybrid orbitals have equal s and p character.

False

sp² hybrid use one s orbital and 2 p orbital for hydridisation. Hence sp² hybrid orbitals have 1/3 s character and 2/3 p character.

6. All the Al-Cl bonds in Al2Cl6 are equivalent. (JEE 1989)

False

The terminal Al-Cl bonds are different from the bridge Al-Cl bonds.

7. Nitric oxide, though an odd electron molecule, is diamagnetic in liquid state. (JEE 1991)

False

In liquid state, some dimerization takes place, but it is only partial. So it is still paramagnetic only.

8. Dipole moment of CH3F is greater than CH3Cl. (JEE 1993)
False

Bond distance is more in CH3Cl and hence more dipole moment.
Dipole moment = charge * distance