Question 1

According to Valence Bond Theory, what is the main requirement for a covalent bond to form between two atoms?

Accepted Answer

The atomic orbitals must overlap with significant electron density between the nuclei.

Question 2

Which type of hybridization is present in the central carbon atom of methane ($$CH_4$$)?

Accepted Answer

$$sp^3$$

Question 3

What is the molecular geometry of a molecule with $$sp^2$$ hybridization on the central atom?

Accepted Answer

Trigonal planar

Question 4

In the formation of $$H_2$$, which orbitals overlap to form the sigma ($$\sigma) $$bond?

Accepted Answer

Two $$1s$$ orbitals

Question 5

Which of the following molecules has a central atom with $$sp$$ hybridization?

Accepted Answer

$$CO_2$$

Question 6

How many sigma ($$\sigma) $$and pi ($$\pi) $$bonds are present in the molecule $$C_2H_4 ($$ethene)?

Accepted Answer

5 $$\sigma$$, 1 $$\pi$$

Question 7

Which statement best describes the difference between sigma ($$\sigma) $$and pi ($$\pi) $$bonds?

Accepted Answer

Sigma bonds result from end-to-end overlap along the internuclear axis, while pi bonds result from side-to-side overlap above and below the axis.

Question 8

A molecule has a central atom with $$sp^3$$ hybridization and two lone pairs. What is its expected molecular geometry?

Accepted Answer

Bent

Question 9

Which of the following best explains why $$He_2$$ does not exist under normal conditions?

Accepted Answer

The bond order is zero, meaning no net bonding.

Question 10

What is the bond order of $$O_2$$ according to Molecular Orbital Theory?

Accepted Answer

$$2$$

Question 11

Which molecule is predicted to be paramagnetic based on its molecular orbital diagram?

Accepted Answer

$$O_2$$

Question 12

A molecule has a central atom with $$sp^2$$ hybridization and one lone pair. What is its expected molecular geometry?

Accepted Answer

Bent

Question 13

Which of the following statements about hybrid orbitals is correct?

Accepted Answer

Hybrid orbitals are degenerate and can form stronger bonds than unhybridized orbitals.

Question 14

What is the hybridization of the central atom in $$NH_3$$?

Accepted Answer

$$sp^3$$

Question 15

Which of the following molecules contains a triple bond?

Accepted Answer

$$C_2H_2$$

Question 16

If a molecule has a bond order of $$1.5$$, what does this indicate about its bonding?

Accepted Answer

It has delocalized electrons and resonance.

Question 17

Which of the following is a consequence of molecular orbital theory that cannot be explained by valence bond theory?

Accepted Answer

The paramagnetism of $$O_2$$ due to unpaired electrons in molecular orbitals.

Question 18

In $$NO_3$$^-$$, what is the bond order between nitrogen and oxygen atoms?

Accepted Answer

$$1.33$$

Question 19

Which hybridization corresponds to a steric number of 4?

Accepted Answer

$$sp^3$$

Question 20

A molecule has a central atom with $$sp^3$$ hybridization, one lone pair, and three bonded atoms. What is its molecular geometry?

Accepted Answer

Trigonal pyramidal

Bonding Theories: Hybridization and Molecular Theories

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