$\\pi$ bonds result from side-by-side overlap of unhybridized p orbitals

Question 1

According to VSEPR theory, what is the primary factor that determines the geometry of a molecule?

Accepted Answer

The repulsion between valence electron pairs

Question 2

Which VSEPR notation correctly describes a molecule with three bonding groups and one lone pair on the central atom?

Accepted Answer

$AB_3E_1$

Question 3

What is the bond angle in a molecule with a trigonal planar geometry?

Accepted Answer

$120^\circ$

Question 4

Which property is NOT directly influenced by molecular structure?

Accepted Answer

Atomic number

Question 5

The dipole moment of a polyatomic molecule is determined by:

Accepted Answer

The vector sum of individual bond dipoles

Question 6

Which of the following molecules is nonpolar due to its geometry, despite having polar bonds?

Accepted Answer

$CO_2$

Question 7

Which principle states that electrons occupy orbitals singly with parallel spins before pairing?

Accepted Answer

Hund's Rule

Question 8

Why is hydrogen diatomic ($H_2$) while helium is not?

Accepted Answer

Helium's antibonding molecular orbital is filled, leading to destabilization

Question 9

Which type of orbital overlap results in a sigma ($\sigma$) bond?

Accepted Answer

Direct (axial) in-phase overlap

Question 10

What is the hybridization of the central carbon atom in methane ($CH_4$)?

Accepted Answer

$sp^3$

Question 11

Which statement best explains why $CO_2$ is nonpolar?

Accepted Answer

It has polar bonds but a linear geometry, causing dipoles to cancel

Question 12

What is the electronic configuration of oxygen ($^8O$) in terms of orbital filling?

Accepted Answer

$1s^2 2s^2 2p^4$

Question 13

Which of the following is true about pi ($\pi$) bonds compared to sigma ($\sigma$) bonds?

Accepted Answer

$\pi$ bonds result from side-by-side overlap of unhybridized p orbitals

Question 14

Which hybridization is associated with a linear molecular geometry?

Accepted Answer

$sp$

Question 15

In the context of molecular orbitals, what does constructive interference between atomic orbitals lead to?

Accepted Answer

Formation of a bonding molecular orbital

Question 16

Which of the following molecules has a net molecular dipole moment?

Accepted Answer

$CH_2Cl_2$

Question 17

What is the bond angle expected in a molecule with $sp^3$ hybridization?

Accepted Answer

$109.5^\circ$

Question 18

Which rule explains why electrons fill orbitals with the lowest energy first?

Accepted Answer

Aufbau Principle

Question 19

Which of the following statements about atomic orbitals is correct?

Accepted Answer

The probability of finding electrons in the nodal region is zero

Question 20

Which of the following best describes the difference between $sp^2$ and $sp^3$ hybridization?

Accepted Answer

$sp^2$ hybridization involves three orbitals and forms trigonal planar geometry, while $sp^3$ involves four orbitals and forms tetrahedral geometry

Molecular Geometry, Orbitals, and Hybridization: Foundations for Organic Chemistry

Study Guide - Practice Questions